L I B R.AR.Y OF THE UNIVERSITY Of ILL1 NOI5 THE MEXICAN AND CENTRAL AMERICAN LIZARDS OF THE GENUS SCELOPORUS BY HOBART M. SMITH W XLTKU RATHBONE BACON SCHOLAR SMITHSONIAN INSTITUTION IHE LIBRARY OF THE UNIVERSITY OF ILLINOIS ZOOLOGICAL SERIES FIELD MUSEUM OF NATURAL HISTORY VOLUME 26 JULY 27, 1939 PUBLICATION 445 Natural Htstorv THE MEXICAN AND CENTRAL AMERICAN LIZARDS OF THE GENUS SCELOPORUS BY HOBART M. SMITH WALTER RATHBONE BACON SCHOLAR SMITHSONIAN INSTITUTION LIBRARY OF THE /U/G 15 1939 ZOOLOGICAL SERIES FIELD MUSEUM OF NATURAL HISTORY VOLUME 26 JULY 27, 1939 PUBLICATION 445 & IN THE UNITED STATES OF AMERICA BY FIELD MUSEUM PRESS CONTENTS PAOB List of Illustrations 5 Introduction 9 Geographical Trends in Variation 12 Biotic Provinces of Mexico 14 Regional Lists 19 Method of Treatment 23 Definition of the Genus 28 Arrangement of the Species in Groups 29 Key to the Groups of SceZoporws 30 Systematic List 32 Forraosus Group 32 Spinosus Group 59 Undulatus Group 172 Graciosus Group 176 Grammicus Group 177 Megalepidurus Group 199 Poinsettii Group 209 Variabilis Group 236 Merriami Group 284 Maculosus Group 290 Chrysostictus Group 294 Siniferus Group 300 Utiformis Group 324 Scalaris Group 330 Pyrocephalus Group 361 Bibliography 378 Index . 395 LIST OF ILLUSTRATIONS PLATES 1. Sceloporus formosus formosus, Chilpancingo, Guerrero. Sceloporus merriami annulatus, Glenn Spring, Texas. 2. Sceloporus asper, Uruapan, Michoacan. 3. Sceloporus salvini, Jalapa, Vera Cruz. Sceloporus formosus malachiticus, Boquete, Panama. 4. Sceloporus lundelli lundelli, Hacienda Balchacaj, Campeche. Sceloporus orcutti licki, San Bartolo, Lower California. 5. Sceloporus lunaei, Guatemala. Sceloporus lundelli gaigeae, Merida, Yucatan. 6. Sceloporus acanthinus, type of S. guentheri. 1. Head scales of Sceloporus acanthinus (from type of S. guentheri). 8. Sceloporus edwardtaylori, Tehuantepec, Oaxaca. 9. Sceloporus melanorhinus, Hacienda El Sabino, Michoacan. 10. Sceloporus melanorhinus, ventral views of specimens on Plate 9. 11. Sceloporus spinosus spinosus, Maravatio, Michoacan. Sceloporus spinosus spinosus, El Salado, San Luis Potosi. Sceloporus spinosus spinosus, Alseseca, Puebla. Sceloporus horridus horridus, Chilpancingo, Guerrero. 12. Sceloporus horridus albiventris, Tepic, Nayarit. Sceloporus horridus horridus, Cuernavaca, Morelos. 13. Sceloporus olivaceus, Rio Grande City, Texas. 14. Sceloporus olivaceus, Huasteca Canon, near Monterrey, Nuevo Le6n. 15. Sceloporus magister magister, Kanab, Utah. Sceloporus clarkii boulengeri, Presidio, Sinaloa. 16. Sceloporus heterolepis (from Boulenger), Jalisco. Sceloporus microlepidotus disparilis, Rio Grande City, Texas. 17. Sceloporus pictus, Acultzingo, Puebla. Sceloporus pictus, Puebla. Sceloporus megalepidurus, Totalco, Vera Cruz. 18. Sceloporus ferrariperezi binocularis, between Pablillo and Alamar, Nuevo Le6n. Sceloporus serrifer plioporus, Lim6n, Tamaulipas. 19. Sceloporus couchii, Huasteca Canon, near Monterrey, Nuevo Le6n. Sceloporus couchii, Sabinas Hidalgo, Nuevo Le6n. 20. Sceloporus cozumelae, Cozumel Island, Yucatan. Sceloporus aeneus bicanthalis, Cruz Blanca, Vera Cruz. Sceloporus scalaris scalaris, Mexico City. 21. Sceloporus teapensis, San Agustin, British Honduras. 22. Sceloporus variabilis variabilis, Tierra Colorado, Vera Cruz. Sceloporus variabilis variabilis, Las Vigas, Vera Cruz. 23. Sceloporus variabilis smithi, Quiengola Mountains, near Tehuantepec, Oaxaca. 24. Sceloporus chrysostictus, Yucatan. Sceloporus squamosus, Tapachula, Chiapas. 25. Sceloporus siniferus, between Rincon and Cajones, Guerrero. Sceloporus siniferus, El Treinte, Guerrero. 5 6 LIST OF ILLUSTRATIONS 26. Sceloporus utiformis, Hacienda El Sabino, Michoacan. Sceloporus utiformis, Uruapan, Michoacan. 27. Sceloporus jalapae, Chazumba, Oaxaca. Sceloporus jalapae, Canada de Morelos, Puebla. 28. Sceloporus nelsoni, Mazatlan, Sinaloa. 29. Sceloporus pyrocephalus, Hacienda El Sabino, Michoacan. Sceloporus pyrocephalus, north of Rio Balsas, Guerrero. 30. Sceloporus pyrocephalus, ventral surfaces of specimens shown in Plate 29. 31. Sceloporus gadoviae, Hacienda El Sabino, Michoacan. TEXT FIGURES PAGE 1. The biotic provinces of Mexico 15 2. Nomenclature of head scales of Sceloporus employed in the present paper . 23 3. Phylogeny of the groups of Sceloporus 28 4. Phylogeny of the formosus group 33 5. Distribution of Sceloporus asper, S. salvini, and S. formosus formosus. . . 36 6. Distribution of Sceloporus formosus smaragdinus and S. f. malachiticus in Central America 42 7. Phylogeny of the spinosus group 59 8. Distribution of the primitive forms of the spinosus group 67 . 9. Head scales of the type of Sceloporus edwardtaylori 79 10. Distribution of Sceloporus melanorhinus, S. spinosus spinosus, and S. s. caeruleopunctatus 88 11. Distribution of the subspecies of Sceloporus horridus and S. olivaceus ... 99 12. Distribution of the subspecies of Sceloporus clarkii and S. orcutti . . . .120 13. Distribution of the subspecies of Sceloporus magister in Mexico 148 14. Variation in number of femoral pores in the subspecies of Sceloporus magister 167 15. Phylogeny of the grammicus and megalepidurus groups 178 16. Lateral nuchal scales of Sceloporus grammicus 181 17. Lateral nuchal scales of Sceloporus microlepidotus microlepidotus .... 185 18. Distribution of the forms of the grammicus group 197 19. Distribution of Sceloporus megalepidurus and S. pictus 200 20. Head scales of Sceloporus megalepidurus 205 21. Phylogeny of the poinsettii group 209 22. Head scales of Sceloporus serrifer serrifer 211 23. Distribution of Sceloporus serrifer, S. ferrariperezi, and S. bulleri .... 213 24. Head scales of Sceloporus ferrariperezi ferrariperezi 215 25. Head scales of Sceloporus bulleri 217 26. Head scales of Sceloporus mucronatus mucronatus 218 27. Distribution of Sceloporus mucronatus, S. cyanogenys, and S. poinsettii . .219 28. Head scales of Sceloporus mucronatus omiltemanus 220 29. Head scales of Sceloporus cyanogenys 222 30. Head scales of Sceloporus poinsettii 223 31. Head scales of Sceloporus lineolateralis 225 32. Head scales of Sceloporus jarrovii jarrovii 226 33. Distribution of Sceloporus lineolateralis and S. jarrovii 228 34. Head scales of Sceloporus jarrovii minor 229 35. Head scales of Sceloporus jarrovii immucronatus 231 LIST OF ILLUSTRATIONS 7 PAGE 36. Head scales of Sceloporus ornatus ornatus 232 37. Distribution of Sceloporus ornatus and S. dugesii 233 38. Head scales of Sceloporus ornatus caeruleus 233 39. Head scales of Sceloporus dugesii dugesii 234 40. Head scales of Sceloporus dugesii intermedius 235 41. The postfemoral dermal pocket of Sceloporus variabilis marmoratus . . . 237 42. Phylogeny of the variabilis, maculosus, and merriami groups 238 43. Distribution of Sceloporus couchii, S. teapensis, and S. cozumelae .... 241 44. Head scales of Sceloporus parvus parvus 252 45. Distribution of Sceloporus variabilis 264 46. Distribution of Sceloporus maculosus, S. parvus, and S. merriami .... 284 47. Head scales of Sceloporus maculosus 292 48. Phylogeny of the siniferus group 300 49. Distribution of Sceloporus carinatus and S. siniferus 302 50. Distribution of Sceloporus ochoterenae and S. cupreus 306 51. Head scales of Sceloporus ochoterenae 309 52. Distribution of Sceloporus squamosus 320 53. Distribution of Sceloporus utiformis and S. gadoviae 326 54. Phylogeny of the scalaris group 331 55. Head scales of Sceloporus jalapae 334 56. Distribution of Sceloporus jalapae, S. goldmani, S. scalaris, and S. chrysostictus 335 57. Distribution of Sceloporus aeneus aeneus and S. a. bicanthalis 357 58. Phylogeny of the pyrocephalus group 362 59. Distribution of Sceloporus nelsoni and S. pyrocephalus 369 THE MEXICAN AND CENTRAL AMERICAN LIZARDS OF THE GENUS SCELOPORUS BY HOBART M. SMITH 1 INTRODUCTION The lizards of the iguanid genus Sceloporus form one of the largest, most progressive, and most recent groups among the reptiles of the New World. Their evolutionary success is accompanied by great variability, and since distribution is continuous, with frequent inter- gradation through chains of subspecies, and with the further diffi- culty that aberration is sometimes difficult to distinguish from geographic variation, the taxonomy of the genus is especially difficult. Attractive problems in species formation and geographical distri- bution are presented, and their solution is brought within reach by the fact that these lizards are frequently abundant and relatively easy to observe and collect. The problems in this genus were recommended by Cope "as an excellent piece de resistance for those persons who do not believe in the doctrine of derivation of species." Authors who have dealt with the genus as a whole have disagreed to a surprising extent in their arrangement and evaluation of the species. They tend to extremes, either recognizing individual variants as named forms, or lumping distinct forms under a single name. Boulenger's "Revision of the lizards of the genus Sceloporus" of 1897 may be cited as an example of the lumping tendency and Cope's treatment in "The Crocodilians, Lizards, and Snakes of North America" tends toward splitting. More recently, C. E. Burt has combined under single names species which are here regarded as distinct. Conditions for a detailed study of the genus are now more propitious than at any previous time; the collections now available far more nearly approach adequacy for the solution of the main problems; and the application of the modern concept of geographic races solves many of the difficulties which perplexed the students of the past century. The importance of familiarity with the creatures in life, of seeing them in their natural environments, and of having fresh material to study in the laboratory can scarcely be overemphasized. In the course of my own field experience in Mexico, I have had the 1 Walter Rathbone Bacon Scholar, Smithsonian Institution. 9 10 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 advantage of observing and collecting 69 of the 95 recognized forms in their natural surroundings. Material from certain critical areas is still lacking, and more direct evidence of relationships is frequently to be desired. The conclusions now presented are accordingly tentative. My studies on the genus Sceloporus began in the fall of 1932, and have been pursued throughout the subsequent years as time per- mitted. Beginning in the attempt to identify specimens collected in Mexico during the summer of 1932, the studies were expanded in following years. With renewed expeditions to Mexico, emphasis has been placed on the Mexican and Central American groups of species within the genus. The subgroups found north of the Mexican border in the United States are being studied in detail by Dr. Clinton V. MacCoy and Dr. Charles E. Burt. Hence the synopsis given here of the undulatus and graciosus groups, which fall mainly within the borders of the United States, is brief. The Graduate Research Council of Kansas University gave financial aid during the scholastic years of 1934 and 1935, materially contributing to the progress of these studies, and making possible the preparation of many of the drawings. The greater part of the work, however, was completed in 1936 and 1937 during tenure of a National Research Fellowship and while laboratory space in an environment favorable for herpetological research was supplied by the Museum of Zoology of the University of Michigan. The considerable collections of Mexican reptiles in Field Museum obtained by the Museum's expeditions in 1901, 1903, and 1904 include numerous specimens of various species of Sceloporus. This material was examined at Field Museum in the course of repeated visits. The fresh Mexican collections of this genus made by Dr. E. H. Taylor and myself since 1932 amount to 2,996 specimens. Half of this collection, representing 57 species, and including nine of the types of the new forms described, has been deposited in the reference collections of Field Museum of Natural History. While not yet as complete as might be desired, this study would never have progressed thus far without the opportunities, aid, and encouragement afforded by the tutor under whose direction the problem was originally undertaken, and who has my deepest appreci- ation Dr. Edward H. Taylor. I am especially indebted also to Mrs. Helen T. Gaige and Mr. Karl P. Schmidt for many favors and for kindly interest which have been of very material aid. Numerous other individuals have afforded valuable aid in many ways. I wish to thank in particular Mr. Joseph R. Bailey, Mr. 1939 MEXICAN LIZARDS SMITH 11 Reeve Bailey, Dr. Thomas Barbour, Mr. Charles E. Bogert, Sr. Julio Raymond Bresson, Mr. C. D. Bunker, Dr. Doris Cochran, Mr. David H. Dunkle, Dr. E. R. Dunn, Sr. Emilio del Rio, Dr. H. W. Fowler, Mr. F. M. Gaige, Sr. Pedro Gal van, Dr. Howard K. Gloyd, Dr. Joseph Grinnell, Dr. Norman Hartweg, Mr. C. W. Hibbard, Dr. Howard R. Hill, Dr. Carl L. Hubbs, Mr. C. F. Kauffeld, Mr. L. M. Klauber, Dr. H. H. Lane, Dr. Jean M. Linsdale, Mr. Arthur Loveridge, Mr. John T. Martin, Sr. Rafael Martin del Campo, Mr. and Mrs. Robert Miller, Sr. Adolfo Morales, Dr. Walter Mosauer, Dr. George S. Myers, Mr. Walter L. Necker, Mr. M. Graham Netting, Dr. G. K. Noble, Dr. Isaac Ochoterena, Mr. James A. Oliver, Dr. R. H. Painter, Mr. Benjamin Shreve, Mr. Joseph R. Slevin, Dr. Leonhard Stejneger, Dr. L. C. Stuart, Dr. Vasco M. Tanner, Mr. H. Devlin Thomas, Dr. C. F. Walker, Dr. A. H. Wright, and Dr. A. M. Woodbury. The drawings have been made by Miss Myra Wildish, Mr. Carol Johnson, Mr. Russell Chezem, and Mr. Maxim Eliashevich, all of the University of Kansas, and by Miss Grace Eager of the University of Michigan. Most of the photographs were taken by Mr. Oren Bingham of the University of Kansas and by Mr. F. W. Ouradnick of Ann Arbor, Michigan. The photographs of preserved specimens were taken by immersing the specimens in water between glass plates. Text figure 55 is reproduced through the courtesy of the Biological Society of Washington; text figures 20, 44, 47, and 51 through the courtesy of the Kansas Academy of Science; and text figures 2, 24, 26, 28-32, 34-36, and 38-40 through the courtesy of the University of Kansas. Material in the following collections has been examined: KU Dyche Natural History Museum, University of Kansas. EHT Collection of Edward H. Taylor. ERD Collection of Emmett R. Dunn. KSC Kansas State College, Manhattan. USNM United States National Museum. AMNH American Museum of Natural History. MCZ Museum of Comparative Zoology. ANSP Academy of Natural Sciences of Philadelphia. CM Carnegie Museum, Pittsburgh. UMMZ University of Michigan Museum of Zoology. FMNH Field Museum of Natural History. CHS Chicago Academy of Sciences. UU University of Utah. 12 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 BYU Brigham Young University. MVZ Museum of Vertebrate Zoology. CAS California Academy of Sciences. LSJU Leland Stanford University. LAM Los Angeles Museum of Natural History. LMK Collection of L. M. Klauber. WM Collection of Walter Mosauer. SDSNH San Diego Society of Natural History. The number of specimens included in the scope of this study, in these collections, totals approximately 17,500. My first opportunity to collect specimens of this genus occurred in the summer of 1929, when I accompanied Dr. and Mrs. Howard K. Gloyd on a brief collecting trip through Kansas, Colorado, and Utah. In the summer of 1930, I again collected with Dr. and Mrs. Gloyd in Texas, New Mexico, Arizona, and California, and in 1931 I accompanied Dr. and Mrs. R. H. Painter in Texas and New Mexico. Introduction to the Mexican forms was made possible by Dr. Edward H. Taylor, whom I accompanied during the summer of 1932 on an expedition covering seventeen central and northern Mexican states. In the summer of 1934 Mr. David H. Dunkle and I again ventured into Mexico, collecting in the northern states. A third trip, which covered most of the other states of Mexico, was undertaken during the summer of 1935. In 1936 Mr. H. Devlin Thomas and I spent several months in Yucatan and Campeche. GEOGRAPHICAL TRENDS IN VARIATION Body size and size of scales. In some groups of reptiles there is an apparent decrease in size of scales from the southern part of the range to the northern. Data derived from the present study of Sceloporus do not support this generalization. The forms in which a definite trend toward decrease in size of scales is discernible from south to north are: Southern Northern formosus malachiticus /. smaragdinus acanthinus (southern) acanthinus (northern) occidentalis biseriatus o. occidentalis undulatus undulatus u. fasciatus undulatus tristichus u. elongatus graciosus vandenburgianus g. gracilis variabilis variabilis variabilis marmoratus pictus megalepidurus There are practically as many cases in which decrease in size of scales takes place in the opposite direction. 1939 MEXICAN LIZARDS SMITH 13 Southern Northern formosus smaragdimis /. formosus orcutti licki o. orcutti spinosus caeruleopunctatus s. spinosus microlepidotus microlepidotus m. disparilis parvus scutulatus parvus parvus pyrocephalus nelsoni mucronatus omiltemanus m. mucronatus squamosus (southern) squamosus (northern) It has also been suggested that scales tend to decrease in size with increase in altitude. While this seems to be true in some cases, there are as many in which it is not true. No clear examples of reduction of body size from the southern part of the range to the north, or with increasing altitude, can be discerned in the Mexican forms. In two groups (undulatus and graciosus) progressive decrease in size of scales toward the north and with increase of elevation, and decrease in body size from south to north do seem to be demonstra- ble. These general trends are evidently much more clearly defined in forms occurring north of the 30th parallel. Some members of the poinsettii and spinosus groups, which fail to show this trend, range northward beyond this limit, but they may be disregarded as belong- ing to groups with their principal concentration of species and sub- species farther south. Selection of single factors for such correlations is, of course, inherently erroneous, for it is certain that more than one factor is correlated with scale and body size. In Mexico and Central America, where environmental conditions are relatively stable only over small areas, such correlations are bound to be obscure. In the United States, where large areas have relatively uniform environ- mental conditions, or where changes tend to be more gradual in any given direction, generalizations tend to be more significant. Trends in breeding habits. All members of the poinsettii, micro- lepidotus, and formosus groups, as well as some (perhaps all) members of the scalaris group, are ovoviviparous. Schmidt (in Hesse, Allee, and Schmidt, 1937) states that microlepidotus is oviparous at the base of Mount Orizaba in Mexico, and viviparous at high levels. This I am inclined to doubt, and Mr. Schmidt and I have searched the literature for the authority for this statement without success. The species of Sceloporus occurring at high altitudes in Mexico and the southern United States are ovoviviparous, oviparous species being entirely excluded, so far as known. All species occurring at elevations above approximately 10,000 feet belong to one of the three groups of ovoviviparous species. As the elevation is decreased, 14 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 oviparous species gradually replace the ovoviviparous species in abundance, until at elevations of 1,000 feet or lower, only a few ovoviviparous species occur (e.g., serrifer, poinsettii, cyanogenys, microlepidotus disparilis). It is of interest that Sceloporus parallels in this respect the condition discovered by Weekes (1933) in Australian lizards of the family Scincidae at high altitudes. BIOTIC PROVINCES OF MEXICO The position of Mexico is, as generally recognized, intermediate between the Nearctic and Neotropical regions. The Nearctic region includes the plateau and adjacent mountain ranges, Lower California, and the coasts of Mexico southward approximately to the Tropic of Cancer. The Neotropical region extends northward through Central America to the Isthmus of Tehuantepec, and north- ward along both coasts. On the Pacific side, the Neotropical region extends nearly to Mazatlan, and up the Rio Balsas basin to southern Puebla; on the east, it extends well north of Tampico, almost exactly to the Tropic of Cancer. Two of the generally recognized subregions of the Nearctic occur in Mexico: the Rocky Mountain and the Calif ornian. The Cali- fornian subregion, however, enters Mexico only in extreme north- western Lower California. The Neotropical part of Mexico falls entirely within the "Mexican subregion." Eighty forms of Sceloporus occur in Mexico. Fifty-six of these are confined to the Nearctic region, and 18 to the Neotropical. Five, which occur in both regions, seem to be essentially Neotropical; two of these enter the Nearctic through the Balsas basin (gadoviae, h. horridus), two over the mountain range south of Lake Chapala (utiformis, horridus oligoporus), and one over the middle of the isthmus of Tehuantepec (variabilis variabilis). THE NEOTROPICAL PROVINCES The Mexican subregion is composed of at least seven provinces which are defined by physiographic, climatic, and faunal character- istics. In this summary they are defined largely on the basis of physiography and of data afforded by the distribution of Sceloporus. Climatic data and information on the distribution of other land vertebrates in Mexico, which would be of especial interest for com- parison with the system here proposed, are as yet quite inadequate for this purpose. The provinces of the Mexican subregion (in Mexico) thus defined are as follows: Chiapan Plateau (CP), Lower Balsan (LB), Pete"n (P), Tapachulan (TAP), Tehuantepecan (TEH), 1939 MEXICAN LIZARDS SMITH 15 Vera Cruzian (VC), and Yucatecan (YUC). Definition of these provinces with the scelopori occurring in them follow. Chiapan Plateau. An elevated region extending westward to the isthmus of Tehuantepec and eastward into Guatemala; its southern edge is marked a few miles inland by a very abrupt, high escarp- ment which increases in elevation toward the Guatemalan border; FIG. 1. The biotic provinces of Mexico. Boundary of Nearctic and Neo-trop- ical regions shown in red. Abbreviations for the provinces: A, Guerreran; AC^ Austrocentral; AOC, Austro-occidental; AOR, Austro-oriental; AP, A'j^ala^k^n; ^*tf>* ARIZ, Arizonian; CHI, Chihuahuan; CP, Chiapan Plateau; D, Durangan; LB, (J Lower Balsan; OH, Oaxacan Highland; PETEN, PetSn; SIN, Sinaloan; TAM, Tamaulipan; TAP, Tapachulan; TEH, Tehuantepecan; UB, Upper Balsan; VC, Vera Cruzian; YUC, Yucatecan. the northern boundary is irregular, much excavated by rivers and valleys. 1 carinatus formosus smaragdinus variabilis variabilis (VC, AOR) Tapachulan. A coastal region south of the Chiapan Plateau province, extending from a region just west of the western Chiapas border into Guatemala. acanthinus squamosus siniferus (TEH, LB) 1 Abbreviations in parentheses refer to other provinces in which the species or subspecies occurs. If no abbreviation is given, the form is restricted to the province for which it is listed. 16 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 Peten. An area north of the Chiapan Plateau province and on the Atlantic drainage of the isthmus, extending northwest along the coast about to the Rio Papaloapam; on the north, approximately to the 20th parallel; on the west, into Guatemala and British Hon- duras. lundelli lundelli chrysostictus (YUC) teapensis serrifer plioporus (VC) Yucatecan. The Yucatan Peninsula north of approximately the 20th parallel. cozumelae serrifer serrifer lundelli gaigeae chrysostictus (P) Vera Cruzian. The coastal region north of Rio Papaloapam approximately to the Tropic of Cancer. The region is defined by the absence of certain species of Sceloporus as much as by the presence of others. variabilis variabilis (AOR, CP) serrifer plioporus (P) Tehuantepecan. A semiarid region in Oaxaca, extending south- ward from the Oaxacan Highland and Austroral provinces to the coast, eastward nearly to the Chiapas border, and westward approxi- mately to the Rio Verde. edwardtaylori siniferus (TAP, LB) melanorhinus (LB) variabilis smithi Lower Balsan. An irregularly outlined area, extending along the coast from the Rio Verde in Oaxaca to a region just south of Mazatlan in Sinaloa; the province extends up the Rio Balsas to northern Oaxaca and southwestern Puebla. horridus albiventris horridus horridus (UB, A) ochoterenae horridus oligoporus (AOC, AC) pyrocephalus melanorhinus (TEH) gadoriae (UB) siniferus (TEH, TAP) utiformis (AOC) THE NEARCTIC PROVINCES The Rocky Mountain subregion of the Nearctic is composed (in Mexico, excluding Lower California) of twelve provinces: Oaxa- can Highland (OH), Guerreran (A), Upper Balsan (UB), Austro- central (AC), Austro-occidental (AOC), Austro-oriental (AOR), Chi- huahuan (CHI), Sinaloan (SIN), Tamaulipan (TAM), Arizonan (ARIZ), Apachian (AP), and Durangan (D). The Apachian, Durangan, and Sinaloan provinces were proposed by William H. Burt (1938, 39, pp. 1-77, maps 1-26). The Tamauli- pan province is that proposed by J. A. Allen (1892, 4, pp. 241-243) 1939 MEXICAN LIZARDS SMITH 17 and redefined by Dice 1 (1937, 12, pp. 265-268). The Austro-oriental, Austrocentral and Austro-occidental provinces were defined by Cope (1896, 30, pp. 1020-25). Oaxacan Highland. A small, elevated tract, mostly grassy plains, south of the upper Rio Balsas and the Sierra Oriental ; extend- ing southward approximately to San Pedro El Alto, and to the Rio Tehuantepec on the east. cupreus jalapae (UB) spinosus caeruleopunctatus microlepidotus microlepidotus (AC, formosus formosus (A) AOC, AOR, A) mucronalus omiltemanus (A) Guerreran. The southern edge of the plateau south of the Rio Balsas in Guerrero and Oaxaca, northward on the east side along the narrow mountain chain to approximately Mirador, Vera Cruz; southward along the eastern mountain ridge to the isthmus of Tehuantepec. salvini horridus horridus (UB, LB) aeneus bicanlhalis (AOR) m. microlepidotus (AC, AOC, AOR, formosus formosus (OH) OH) mucronalus omiltemanus (OH) Upper Balsan. A desert or semiarid region at the upper limits of the Rio Balsas and near the lower end of the interior plateau (Austrocentral) province. This district occupies a definite path of communication between the Neotropical and Nearctic regions. pictus horridus horridus (LB, A) gadoviae (LB) jalapae (OH) spinosus spinosus (AC) Austrocentral. A broad area on the interior of the Mexican plateau, bordered on the east, south (except the interval noted above), and west by the peripheral mountain ranges; on the north, the district extends nearly to Saltillo on the east, and beyond Dur- ango (city) on the west. The Upper Austrocentral province en- croaches upon the Chihuahuan in the region of northwestern and central Zacatecas. caulus aeneus aeneus (AOC) dugesii intermedius horridus oligoporus (LB, AOC) ferrariperezi melanogasier microlepidotus disparilis (TAM, goldmani D, AOR) jarrovii minor m. microlepidotus (AOC, AOR, A, parvus parvus OH) scalaris scalaris spinosus spinosus (UB) Austro-occidental. An area of mountain ridges on the southwest edge of the plateau, extending from northern Nayarit, south of Lake 1 The Potosian province proposed by Dice is apparently the same as that here called the Austro-oriental. 18 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 Chapala, eastward south of Lake Cuitzeo, through the southern part of the Distrito Federal to northwestern Puebla. asper aeneus aeneus (AC) bulleri ferrariperezi ferrariperezi (AOR) dugesii dugesii horridus oligoporus (LB, AC) heterolepis m. microlepidotus (AC, AOR, A, OH) scalaris unicanthalis utiformis (LB) Austro-oriental. Mountainous ridges on the eastern edge of the plateau approximately from Mirador northward to Monterrey. ferrariperezi binocularis ferrariperezi ferrariperezi (AOC) jarrovii immucronatus microlepidotus disparilis (TAM, D, megalepidurus AC) mucronatus mucronatus m. microlepidotus (AC, AOC, A, parvus scutulatus OH) aeneus bicanthalis (A) variabilis variabilis (VC, CP) Apachian. The mountains on the western edge of the plateau northward from central Chihuahua to southeastern Arizona. undulatus virgatus jarrovii jarrovii (D) scalaris slevini (D) Sinaloan. Coastal region from a short distance south of Mazat- lan to southern Sonora. clarkii boulengeri nelsoni Durangan. Mountains northward from central Chihuahua southward to northern Nayarit. jarrovii jarrovii (AP) microlepidotus disparilis (TAM, scalaris slevini (AP) AC, AOR) Tamaulipan. A broad coastal area southward from the Rio Grande approximately to the Tropic of Cancer. cyanogenys microlepidotus disparilis (D, AC, olivaceus AOR) variabilis marmoratus undulatus consobrinus (CHI) Chihuahuan. The central area north of the Austrocentral province, east of the western mountain ridges, west of the Tamauli- pan province. couchii ornatus ornatus lineolateralis ornatus caeruleus maculosus poinsettii merriami annulatus undulatus consobrinus (TAM) magister magister (ARIZ) Arizonan. Eastern Sonora, southward approximately to the Rio Mayo; northeastern Lower California. clarkii clarkii magister magister (CHI) The biotic provinces of Lower California, as supported by data on distribution of Sceloporus, appear to be correctly analyzed by 1939 MEXICAN LIZARDS SMITH 19 Grinnell (1928). The data furnished by Sceloporus do not, however, add to that already available concerning the island faunas, as Sceloporus does not seem to have developed island species. The only exception is S. m. lineatulus, on Santa Catalina Island, in the Gulf of California. Forms of Sceloporus in the peninsular provinces are as follows: Colorado Desert (m. magister); San Pedro Martir (o. orcutti, graciosus vandenburgianus) ; San Diegan (o. orcutti, o. biseri- atus); Vizcaino Desert (o. orcutti, m. rufidorsum)', San Ignacio (m. lineatulus, m. monserratensis, o. orcutti) ; Cape (m. zosteromus, o. licki). REGIONAL LISTS The species and subspecies known to occur in each of the various states of Mexico and in the countries of Central America may be listed, as an aid in the identification of small collections. AGUASCALIENTES ferrariperezi melanogaster spinosus spinosus LOWER CALIFORNIA graciosus vandenburgianus magister rufidorsum magister lineatulus magister zosteromus magister magister occidentalis biseriatus magister monserratensis orcutti licki orcutti orcutti CAMPECHE chrysostictus serrifer serrifer lundelli lundelli teapensis CHIAPAS aeanthinus siniferus carinatus squamosus formosus smaragdinus teapensis mucronatus omiltemanus variabilis variabilis CHIHUAHUA clarkii clarkii(l) nelsoni jarrovii jarrovii poinsettii magister magister scalaris slevini microlepidotus disparilis undulatus consobrinus COAHUILA cautus olivaceus couchii ornatus caeruleus goldmani ornatus ornatus jarrovii minor poinsettii merriami annulatus scalaris slevini microlepidotus disparilis undulatus consobrinus variabilis marmoratus COLIMA dugesii dugesii melanorhinus formosus formosus microlepidotus microlepidotusCi) horridus oligoporus pyrocephalus utiformis 20 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 DISTRITO FEDERAL aeneus aeneus ocholerenae(l) ferrariperezi ferrariperezi scalaris scalaris microlepidolus microlepidotus spinosus spinosus DURANGO horridus oligoporus poinsettii jarrovii jarrovii scalaris scalaris lineolateralis scalaris slevini magister magister spinosus spinosus microlepidotus disparilis undulatus consobrinus GUANAJUATO aeneus aeneus microlepidotus disparilis dugesii intermedius microlepidotus microlepidotus ferrariperezi ferrariperezi scalaris scalaris jarrovii minor spinosus spinosus variabilis variabilis GUERRERO aeneus aeneus melanorhinus asper microlepidotus microlepidolus formosus formosus mucronatus omiltemanus gadoviae ochoterenae horridus horridus pyrocephalus horridus oligoporus siniferus utiformis HIDALGO aeneus bicanthalis mucronatus mucronatus ferrariperezi ferrariperezi parvus scutulatus jarrovii immucronatus scalaris scalaris microlepidotus disparilis spinosus spinosus microlepidotus microlepidolus variabilis variabilis JALISCO aeneus aeneus horridus albiventris asper horridus oligoporus bulleri melanorhinus clarkii boulengeri microlepidotus microlepidolus dugesii dugesii nelsoni dugesii intermedius pyrocephalus ferrariperezi melanogaster scalaris scalaris formosus formosus(l) scalaris unicanthalis heterolepis spinosus spinosus utiformis MEXICO aeneus aeneus microlepidotus microlepidotus ferrariperezi ferrariperezi mucronatus mucronatus jarrovii minor scalaris scalaris spinosus spinosus MICHOACAN aeneus aeneus horridus oligoporus asper melanorhinus dugesii intermedius microlepidotus microlepidotus ferrariperezi ferrariperezi pyrocephalus ferrariperezi melanogaster scalaris scalaris gadoviae spinosus spinosus utiformis 1939 MEXICAN LIZARDS SMITH 21 MORELOS aeneus aeneus horridus horridus ferrariperezi ferrariperezi microlepidotus microlepidotus gadoviae ochoterenae siniferus NAYARIT asper jarrovii jarrovii clarkii boulengeri melanorhinus dugesii dugesii nelsoni horridus albiventris scalaris unicanthalis utiformis NUEVO LEON couchii olivaceus cyanogenys parvus parvus ferrariperezi binocularis poinsettii jarrovii minor scalaris slevini microlepidotus disparilis undulatus consobrinus variabilis marmoratus OAXACA aeneus bicanttialis melanorhinus cupreus microlepidotus microlepidotus edwardtaylori mucronatus omiltemanus formosus formosus salvini gadoviae siniferus grammicus spinosus caeruleopunctatus horridus horridus teapensis jalapae variabilis smithi variabilis variabilis PUEBLA aeneus aeneus microlepidotus microlepidotus aeneus bicanthalis mucronatus mucronatus ferrariperezi ferrariperezi mucronatus omiltemanus gadoviae pictus horridus horridus scalaris scalaris jalapae spinosus spinosus megalepidurus variabilis variabilis QUERETARO jarrovii immucronatus variabilis variabilis SAN LUIS POTOSI cautus microlepidotus disparilis ferrariperezi melanogaster parvus parvus goldmani parvus scutulatus jarrovii minor spinosus spinosus variabilis variabilis SINALOA clarkii boulengeri nelsoni horridus albiventris utiformis SONORA clarkii boulengeri magister magister clarkii clarkii nelsoni jarrovii jarrovii scalaris slevini undulatus virgatus 22 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 cyanogenys microlepidotus disparilis olivaceus aeneus bicanthalis ferrariperezi ferrariperezi formosus formosus jalapae jarrovii immucronalus megalepidurus TABASCO teapensis TAMAULIPAS serrifer plioporus spinosus spinosus variabilis marmoratus variabilis variabilis VERA CRUZ mucronatus mucronatus mucronatus omiltemanus pictus salvini serrifer plioporus spinosus spinosus microlepidotus microlepidotus teapensis variabilis variabilis YUCATAN chrysostictus cozumelae cautus ferrariperezi melanogaster horridus oligoporus jarrovii jarrovii lundelli gaigeae serrifer serrifer ZACATECAS jarrovii minor microlepidotus disparili scalaris scalaris spinosus spinosus chrysostictus acanthinus formosus smaragdinus lunaei lundelli lundelli serrifer plioporus acanthinus formosus malachiticus formosus malachiticus formosus smaragdinus formosus malachiticus formosus malachiticus undulatus consobrinus BRITISH HONDURAS lundelli lundelli teapensis GUATEMALA siniferus squamosus teapensis variabilis olloporus variabilis variabilis SALVADOR squamosus variabilis olloporus HONDURAS squamosus variabilis olloporus NICARAGUA squamosus variabilis olloporus COSTA RICA squamosus variabilis olloporus PANAMA formosus malachiticus 1939 MEXICAN LIZARDS SMITH 23 METHOD OF TREATMENT The detailed description of each species is drawn up on a definite plan, from which there is little departure. The descriptions of scutellation are arranged in seven paragraphs, each of which con- siders a certain set of characters. The general plan, with an evalu- ation of the characters, follows. Rugosity and pitting of head scales. Of varying importance. Frontal ridges. Two distinct, rounded ridges originating on the frontal and diverging anteriorly, enclosing between them a distinct depression in the median prefrontal area. Members of the formosus group exhibit these structures most clearly. toculars superciliaries preocular canth -loreal /nasal ',supralabials '/astral nfralabials mental labiomentals (outir TOD) -posbmentals _ labiomanta!s(mniriou) lorilobioh - suboculor infralabials '---& postmental s " ^' ,-tabiomntals (outer rouj '^tobiomcntals^mntr rouj rostral internasals ; - subnasal 7.7-- -nasal feVLl!"'- canbhols "~ frontonasals '-"pref rentals frontal, ant. part supardliarica - frontal, post.part frontoparicbal parietal interparital FIG. 2. Nomenclature of head scales of Sceloporus employed in the present paper (based on S. ferrariperezi melanogaster). Interparietal (occipital). A large median scale at the posterior edge of the head, always single, with a spot marking the position of the parietal foramen. The scale is usually subquadrate, and its rela- tive size is of some importance. The interparietal is relatively quite large at birth, and gradually decreases in proportionate size as the animal attains greater age. In species which attain greatest size, the interparietal is relatively the smallest. Parietals. A single, subtriangular parietal usually borders the interparietal on each side. Occasionally in some species, regularly in others, a second, enlarged, convex parietal occurs posterior to the first. 24 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 Frontoparietals. A single pair of small, rectangular fronto- parietals normally precedes the parietals, separating the interparietal from the row of scales about the supraoculars. The frontoparietals may contact each other medially, or may be separated either by an azygous scale or by contact of the frontal with the interparietal. In some species the frontoparietals are usually divided into four scales. Frontal. A large scale between the orbits, normally trans- versely divided into two sections, the anterior somewhat larger than the posterior. In ornatus the tendency is to lose the posterior portion of the frontal, probably by fusion with adjacent scales. In poinsettii the frontal is usually broken irregularly into several scales. It is significant that in species of the poinsettii group in which the supraoculars are in two rows, the frontal rarely touches the interparietal. The reverse is the case in species having a single row of supraoculars. Some species are characterized by having the anterior section or the entire frontal longitudinally divided. Supraoculars. A series of enlarged scales above the orbit, in some species divided irregularly, in others in two regular rows, and in still other species quite large and entire. Between them and the median head scales there is usually a single row of small scales which may or may not be complete; the number of supraoculars in con- tact with the median head scales is of great importance in certain groups, particularly the spinosus group. Between the supraoculars and superciliaries there may be one, two, or three complete or incom- plete rows of small scales. The number of rows is of importance; in edwardtaylori, for instance, there is but one, nearly obsolete row. Superciliaries. Six superciliaries are always present, the first four imbricating posteriorly, the fifth completely hidden below the' fourth, and the sixth overlapping the posterior part of the fourth. They are occasionally subdivided. Prefrontals. Two rather large scales preceding the frontal, in contact medially, or separated either by contact of the median frontonasal with the frontal or by an azygous scale. Internasals. Two or four pairs of internasals is apparently the normal condition, but this arrangement is seldom realized. The scales are usually irregularly divided. Postrostrals. A row of two to six scales between the rostral and the nasals and internasals; sometimes further subdivided. The num- ber, whether two or more, may be significant. Some species have none, the nasals and internasals being in contact with the rostral. 1939 MEXICAN LIZARDS SMITH 25 Subnasal. A relatively large scale immediately below the nasal, in contact with the anterior can thai and loreal. It is regularly absent in some species. Canthals. One or two scales on the canthus rostralis. The number is of taxonomic importance. In some species the anterior is frequently forced above the canthal ridge by contact of the subnasal and posterior canthal. Loreal. A small scale below the canthals, in contact anteriorly with the subnasal and posteriorly with the preocular. It may rarely be divided into two or three scales. The first canthal occasionally separates the loreal from the subnasal and contacts the rows of scales above the supralabials. Preocular. A small scale, with a heavy keel near its upper pos- terior edge, split off from the anterior end of the subocular. The preocular is, in some species, divided longitudinally. Subocular. A large, curved, elongate scale immediately below the eye, with a heavy keel near its upper edge. Postoculars. Variable, usually two. They follow the subocular, curving posteriorly and upward at the edge of the orbit, and are usually distinguished from the adjacent temporal scales by being keeled and somewhat larger. Lorilabials. The small scales above the supralabials. They are in one or two rows; if the latter, they may be reduced to one at some point below the subocular. One of these rows continues about the snout as the postrostrals in most species. Supralabials. The scales on the upper labial border, excluding the scale at the tip of the snout. The scales of this series are smooth and as a rule nonimbricate, but in certain species are rather strongly imbricate and may be rugose or keeled. Infralabials. The scales on the lower labial border, excluding the scale at the mandibular symphysis. The scales of this series are similar in character to the supralabials. Mental. A median anterior pentagonal or triangular scale bordering the lip. Postmentals. A series of enlarged scales on each side posterior to the mental. The scales are paired; those of the anterior pair are separated from each other by a varying number of scales. The number of postmentals is irregular and of little taxonomic significance. 26 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 Labiomentals. Usually two, sometimes one, series of scales on each side between the postmentals and infralabials. In some species the anterior scale of the outer row may contact the mental, and this condition is of some taxonomic significance. Whei*the anterior scale of the outer row is separated from the mental, it is only by narrow contact of the first infralabial with the first postmental. The inner row of labiomentals, when present, never extends as far forward as the outer row, and the position at which it terminates, in relation to the infralabials, is of considerable taxonomic significance. Gular scales. The modifications such as carination, mucrona- tion, and denticulation of these scales, as well as their relative size, are important. Auricular lobules. These are the scales on the anterior border of the ear. Their number and relative size are important in some species. Temporals. The modifications and relative size of these scales are important. Lateral nuchal pocket. A dermal pocket between the arm and the ear, present in all species of Sceloporus. The lining of the pocket is without scales or only with small, granular scales. The character of the scales surmounting the overlapping fold of skin is of consider- able importance. Gular fold. A complete, structural gular fold (i.e. of granular scales) does not occur in any species of the genus. In a few, however, there is an indication of it in front of the insertion of the foreleg; this rudiment is not to be confused with the lateral nuchal pocket, which is situated anteriorly. Dorsal scales. The modifications and relative size of the scales of the back are of great importance. They are counted in as nearly a straight line as possible, near the mid-dorsal line, from the inter- parietal to a line between the posterior margins of the hind legs. Lateral scales. Size and character of the scales on the sides are to be noted; in some species, particularly of the poinsettii group, the median lateral scales are distinctly larger than the median dorsal scales, while in most species they are smaller. The scale count around the body is taken at the middle. Ventral scales. The modifications of the scales of the ventral surface are to be noted. They are counted in a straight line near (not on) mid-venter, from a line between anterior margin of shoulders to anus. 1939 MEXICAN LIZARDS SMITH 27 Preanals. Scales of the preanal region posterior to the femoral pore series (projected). In some groups these are keeled in females. In a number of species of the poinsettii group they are modified in such a manner as to appear pore-like. Scales of the foreleg. Relative sizes and modifications are noted. The number of lamellae under the fingers is of minor importance. Scales of the hind leg. Size and modifications noted. The num- ber of subdigital lamellae is of greater importance. Femoral pores. A longitudinal series of pits along the postero- ventral border of the thighs. The number of pores in each series, or in the two together, is of much importance. They are always present in Sceloporus, although in horridus oligoporus they may be as few as two on each leg. Caudal scales. Size and character are important. Postanals. Two enlarged, smooth scales immediately posterior to the anus in males. They are present in most groups, but absent or erratic in others. Postfemoral dermal pocket. A small, very distinct, obliquely situated pocket on the base of the tail near the posterior margin of the insertion of the hind leg (sometimes difficult to distinguish in the very young). These pockets occur in all members of the variabilis group, and in maculosus and gadoviae. Coloration. Certain color characteristics are distinctive of groups. The most important single characteristic of the members of the poinsettii group is the presence of a black, light-bordered collar about the neck. The light borders may be incomplete (most nearly incom- plete in a phase of j. jarrovii and in /. melanogaster}, but never absent. Certain species of related groups (grammicus, formosus, spinosus} may have black nuchal collars, but these differ in lacking the light borders. In most species, the males have distinctive lateral belly patches blue or pink in color, usually dark or black bordered; the borders may expand and cover the entire belly. Females of a few forms (notably variabilis smithi) have similar patches. Both males and females of some species are more or less unicolor below; it is of in- terest that in most of these the males have no enlarged postanals, and that it is the female which carries the most conspicuous sec- ondary sex character (keeled preanals). Measurements. The distance from snout to occiput is measured from the posterior edge of the interparietal to the end of the snout, in a plane parallel with the edge of the mouth. The snout to ear 28 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 measurement is taken from the posterior border of the ear, in a line parallel to the median vertical axis of the head. The hind leg is measured along its posterior border, from the insertion of the leg to the tip of the fourth toe, excluding the claw. The fourth toe is measured from the base of the fifth, and does not include the claw. undulatus poinsettn grammicus 'maculosus ' KEELED IN J ; pv rocephalus FEMALES m ^formosus i OVOVI'VIPAROUS A POSTFEMORAL POCKET IN SOME OR ALL SPECIES FIG. 3. Phylogeny of the groups of Sceloporus. The tibia is measured along its anterior border, flexing the tibia back against the femur, holding the metatarsus at right angles to the tibia, and measuring from the inner angle of the tibiometatarsal joint to the proximal end of the tibia. DEFINITION OF THE GENUS Sceloporus Wiegmann. Sceloporus Wiegmann, Isis, 21, p. 369, 1828 (type, Sceloporus torquatus Wieg- mann =ferrariperezi) . 1939 MEXICAN LIZARDS SMITH 29 The definition of the genus Sceloporus offers little difficulty. Within the family Iguanidae it belongs to the typically North American series of genera with femoral pores; its depressed body, imbricate and keeled dorsal scales, enlarged occipital shield, keeled digital lamellae, and distinct tympanum, in combination with the absence of abdominal ribs, collar, gular pouch, pterygoid teeth, and dorsal crest, distinguish it from the other genera of the family. Uta, with a collar, is perhaps directly allied to Sceloporus and presumably derived from one of its branches. Sator, with a compressed body, appears to be another direct ally; otherwise Sceloporus is well isolated from all other iguanid genera. Its center of abundance and diversi- fication is plainly the Mexican plateau and its escarpments. While the depressed body in iguanid lizards is ordinarily asso- ciated with terrestrial habits, the species of Sceloporus are markedly arboricole and petricole. Habitat limitation, however, is not extreme in most species of the genus; and wide distribution and great varia- bility are seen to be correlated with adaptability, or more exactly, "euryoky." ARRANGEMENT OF THE SPECIES IN GROUPS Of the 127 names proposed in the genus, I consider 95 valid. These have been segregated into 15 groups of approximately equiva- lent morphological value. These are necessarily very unequal in number of species, three being monotypic, while the remaining 12 include from two to 21 forms. The interrelations of these groups are shown on the accompanying phylogenetic tree (fig. 3). The groups are as follows: asper formosus formosus acanthinus clarkii clarkii clarkii boulengeri edwardtaylori horridus horridus horridus oligoporus horridus albiventris becki cautus occidentalis occidentalis occidentalis biseriatus Group FORMOSUS formosus malachiticus Group SPINOSUS lunaei lundelli lundelli lundelli gaigeae magister magister magister lineatulus magister monserratensis magister rufidorsum Group UNDULATUS occidentalis taylori undulatus undulatus undulatus consobrinus undulatus elongatus undulatus floridanus formosus smaragdinus salvini magister zosteromus melanorhinus olivaceus orcutli orcutli orcutti licki spinosus spinosus spinosus caeruleopunctatus undulatus garmani undulatus tristichus undulatus virgatus woodi 30 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 graciosus graciosus gramrmcus Group GRACIOSUS graciosus gracilis graciosus vandenburgianus bulleri cyanogenys dugesii dugesii dugesii intermedius ferrariperezi ferrariperezi ferrariperezi melanogaster couchii cozumelae parvus parvus Group GRAMMICUS microlepidotus microlepi- heterolepis dotus microlepidotus disparilis Group MEGALEPIDURUS megalepidurus pictus Group POINSETTII ferrariperezi binocularis jarrovii jarrovii jarrovii immucronatus jarrovii minor lineolateralis mucronatus mucronalus carinatus cupreus aeneus aeneus aeneus bicantlialis gadoviae mucronatus omiltemanus ornatus ornatus ornatus caerideus poinsettii serrifer serrifer serrifer plioporus Group VARIABILIS parvus scutulatus teapensis variabilis variabilis Group MERRIAMI merriami merriami merriami annidatus Group MACULOSUS maculosus Group CHRYSOSTICTUS chrysostictus variabilis marmoratus variahilis olloporus variabilis smithi Group UTIFORMIS utiformis Group SCALARIS goldmani jalapae scalaris scalaris Group PYROCEPHALUS nelsoni siniferus squamosus scalaris slevini scalaris unicanthalis pyrocephalus KEY TO THE GROUPS OF SCELOPORUS 1. Postfemoral dermal pocket present 2 Postfemoral dermal pocket absent 4 2. Postrostral scales absent; nasals and internasals in contact with rostral. maculosus (p. 290) Postrostral scales present; internasals and nasals separated from rostral. . . .3 3. Tail strongly compressed in males, rounded and light pink in females; femoral pores 24 or more on each side pyrocephalus (p. 361) Tail rounded in both sexes, not pink in females; femoral pores 20 or less. variabilis (p. 236) 1939 MEXICAN LIZARDS SMITH 31 4. Lateral body scales not imbricate 5 Lateral body scales imbricate 6 5. Preanal scales keeled in females; males with poorly developed postanals; no distinct belly patches in males; tail over twice length of body. utiformis (p. 324) Preanal scales smooth in females; males with well-developed postanals; lateral belly patches distinct in males; tail less than twice length of body. merriami (p. 284) 6. No postrostrals; nasals and internasals in contact with rostral 7 Postrostrals present; nasal and internasals separated from rostral 8 7. Dorsal scales 50 or more; femoral pores 17 or more; preanals smooth in females scalaris (p. 330) Dorsal scales 46 or less; femoral pores 16 or less; preanals keeled in females. siniferus (p. 300) 8. Ventral scales, at least laterally, pointed, not notched; preanal scales keeled . in females; no lateral belly markings in males; femoral pore series widely separated medially; two postrostrals siniferus (p. 300) Ventral scales notched or, if pointed, femoral pore series closely approxi- mated medially (separated by four scales or less); preanal scales smooth in females 9 9. Males uniform white below; anterior section of frontal longitudinally divided; femoral pore series widely separated medially chrysostictus (p. 294) Males with lateral belly patches distinct or, if not, anterior section of frontal entire 10 10. Femoral pore series closely approximated medially; two postrostrals; lateral scale rows parallel or nearly so; scales on posterior surface of thigh granu- lar; small species scalaris (p. 330) Femoral pore series widely separated medially or, if closely approximated, scales on posterior surface of thigh not granular; lateral scale rows strongly divergent; typically four postrostrals, sometimes three, rarely two 11 11. Scales on posterior surface of thigh granular 12 Scales on posterior surface of thigh not granular 15 12. Dorsal scales highly irregular in size grammicus (p. 177) Dorsal scales subequal in size 13 13. Lateral nuchal scales much smaller than and well differentiated from dorsal nuchal scales; scales of lateral row of dorsal nuchals enlarged, strongly keeled and mucronate grammicus (p. 177) Lateral nuchal scales not well differentiated from dorsal nuchal scales .... 14 14. Throat light blue, barred or mottled with white; lateral belly patches con- fluent medially; preanal scales large, about seven in a row from a line between femoral pore series to anus grammicus (p. 177) Throat not as described or, if so, lateral belly patches not confluent medially and preanal scales smaller 15 15. Scales on posterior surface of thigh granular; femoral pore series widely separated medially, the folds defining the preanal area passing between the femoral pore series; throat mottled with blue and white, never with a distinct, blue spot medially or on either side posteriorly, .graciosus (p. 176) Scales on posterior surface of thigh not granular or, if so, the femoral pore series more closely approximated medially, the folds defining the preanal area not or barely passing between the femoral pore series 16 16. Dorsal, ventral, and lateral scales subequal in size; small species. megalepidurus (p. 199) Dorsal, ventral, and lateral scales distinctly differing in size; large or small species 17 32 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 17. A distinct, dark, light-bordered nuchal collar poinsettii (p. 209) No distinct, dark, light-bordered nuchal collar 18 18. Gular region mottled, not barred nor with a median or two lateral blue spots posteriorly poinsettii (p. 209) Gular region not mottled 19 19. Gular region barred in males and lacking a median posterior dark blue or black spot spinosus (p. 59) Gular region not barred; or, if barred, with a median posterior dark blue or black spot 20 20. Gular region barred in males, with a median posterior dark blue or black spot. undulatus (p. 172) Gular region not barred 21 21. Supraoculars large, separated from superciliaries by no more than one com- plete and one incomplete row of small scales; and one or more of the posterior supraoculars in contact with median head scales . . spinosus (p. 59) Supraoculars large or small; if any of the posterior supraoculars are in con- tact with median head scales, the supraoculars are- separated from super- ciliaries by three or more complete or incomplete rows of small scales ... 22 22. Males lacking lateral belly patches undulatus (p. 172) Males with lateral belly patches 23 23. A pair of dark blue or black spots on posterior part of gular region. undulatus (p. 172) No pair of dark spots on posterior part of gular region 24 24. Three or more rows of small scales between supraoculars and superciliaries; or, if two, the scales of the inner row considerably larger than those of the outer row 25 One complete and one incomplete row of small, subequal scales between supraoculars and superciliaries 27 25. One canthal, or, if two, the first forced above canthal ridge, .formosus (p. 32) Two canthals, the first not forced above canthal ridge 26 26. A broad, black nuchal collar complete about neck dorsally, or anterior section of frontal longitudinally divided formosus (p. 32) Neither true undulatus (p. 172) 27. Frontal ridges present formosus (p. 32) Frontal ridges absent spinosus (p. 59) THE FORMOSUS GROUP 1 Ten species have been described within the formosus group. These are asper Boulenger, formosus Wiegmann, irazuensis Giinther, malachiticus Cope, obscurus Van Denburgh, salvini Giinther, schmidti Jones, smaragdinus Bocourt, taeniocnemis Cope, and viviparus Cope. Of these, I recognize five species and subspecies: asper, formosus formosus, /. malachiticus, f. smaragdinus, and salvini. The characters which, in their combination, distinguish the group from others of the genus are: moderately large size (maximum 1 Approximately 587 specimens examined. 1939 MEXICAN LIZARDS SMITH 33 snout- vent measurement of largest species, 95 mm.; of smallest, 81 mm.); scales on posterior surface of thigh not granular, not less than half the size of preanal scales; supraoculars small, entire or in two rows; posterior supraoculars not regularly in contact with median head scales; a tendency toward development of frontal ridges; GRAMMICUS GROUP SMARAGDINUS FORMOSUS ASPER FIG. 4. Phylogeny of the formosus group. throat not barred, but generally suffused with blue or orange; sides of belly blue in males, usually dark-bordered; a black shoulder spot present, sometimes extending dorsally to form a nuchal collar; and nuchal collar, if present, not light-bordered. The phylogeny of this group is interesting. It is more primitive than the microlepidotus and spinosus groups, which are, in turn, more primitive than the megalepidurus and poinsettii groups, respectively. 34 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 S. salvini is a derivative which has no direct relationship with any other species of its group, or with any other group of Sceloporus. It is therefore thought to have been developed early in the phylogeny of its group. S. f. malachiticus was perhaps developed at more or less the same time and early gave rise to /. formosus, to which asper seems most closely related. S. f. malachiticus later developed another subspecies, /. smaragdinus. The species of the formosus group are largely arboreal, are in general confined to a high altitude (descending to a rather low eleva- tion in Costa Rica), and are, so far as known, ovoviviparous. The subspecies of formosus are known to be ovoviviparous; there are no observations for salvini and asper. KEY TO THE SPECIES AND SUBSPECIES OF THE FORMOSUS GROUP 1. A complete dorsal nuchal collar three or four scales wide in both sexes (some- times broken narrowly in mid-dorsal line); lateral frontonasals separated from median frontonasal; two rows of supraoculars; dorsal scales 39 to 44. salvini (p. 55) No complete nuchal collar; lateral frontonasals in contact with median fronto- nasal (except extreme northern specimens of /. smaragdinus) 2 2. Ventral scales one-fourth size of dorsal scales; largest lateral scales two-thirds size of dorsal scales; anterior section of frontal usually longitudinally divided; sides of belly blue in males, not dark-bordered; gular region immacu- late in males; two canthals; dorsal scales 29 to 35, strongly keeled. asper (p. 51) Ventral scales at least one-half size of dorsal scales; largest lateral scales at least three-fourths size of dorsal scales; anterior section of frontal rarely longitudinally divided; sides of belly blue in males, dark-bordered; gular region blue or orange in males 3 3. Dorsal scales usually 39 or more /. smaragdinus (p. 41 ) Dorsal scales usually 38 or less 4 4. One can thai or, if two, the first usually forced above canthal ridge; males usually with a light line down the center of each dorsal scale row; frontal usually separated from interparietal /. malachiticus (p. 46) Usually two canthals, the first usually not forced above canthal ridge; males usually lacking a light line down the center of each dorsal scale row; frontal usually in contact with interparietal /. formosus (p. 34) Sceloporus formosus formosus Wiegmann. Sceloporus formosus Wiegmann, Herp. Mex., p. 50, pi. 7, fig. 2, 1834; Fitzinger, Syst. Kept., p. 75, 1843; Miiller, Reisen in Mexiko, p. 601, 1865; Bocourt, Ann. Sci. Nat., Zool., (5), 17, No. 10, p. 1, 1873; idem, Miss. Sci. Mex., ZooL, 3, sec. 1, p. 182, pi. 18, figs. 3, 3 a-c, 1874; Duges, Naturaleza, 4, p. 30, 1877; Cope, Proc. Amer. Phil. Soc., 18, p. 265, 1879; Sumichrast, Naturaleza, 6, p. 38, 1882; Carman, Bull. Essex Inst., 16, p. 17, 1884; Duges, Naturaleza, (2), 1, p. 114, 1888; Stejneger, N. Amer. Fauna, 7, p. 178, 1893; Gadow, Proc. Zool. Soc. Lond., 2, pp. 194, 214, 231-232, 1905; idem, Through Southern Mexico, pp. 57, 270, 1908; idem, Zool. Jahrb. Syst., 29, p. 706, 1910; Ruthven, Rept. Mich. Acad. Sci., 14, p. 231, 1912; Gadow, Jorullo, p. 95, 1930. 1939 MEXICAN LIZARDS SMITH 35 Tr opidolepis formosus Dumeril and Bibron, Erp. Gen., 4, pp. 303-304, 1837; Dume'ril, Cat. Meth., p. 77, 1851; Gray, Cat. Liz. Brit. Mus., p. 209, 1845; Lichtenstein, Nomen. Kept. Amph., p. 9, 1856; Jan, Cenni Rept. Mus. Milano, p. 39, 1857; Sumichrast, Ann. Mag. Nat. Hist., (3), 13, p. 507, 1864; idem, Bibl. Univ. Rev. Suisse, 19, p. 61, 1864; idem, Naturaleza, 1, p. 206, 1870 (Tropidolepsis f.); Duges, Naturaleza, 1, p. 143, 1870; Westphal-Castelnau, Congr. Scient. France, 35, p. 285, 1872. Sceloporus malachiticus Sumichrast, Naturaleza, 6, p. 38, 1882 (part). Sceloporus viviparus Cope, Proc. Amer. Phil. Soc., 22, p. 398, 1885 Mirador, Vera Cruz (type, USNM 25073, collected by Sartorius); idem, Bull. U. S. Nat. Mus., 32, p. 36, 1887; Gunther, Biol. Cent.-Amer., Rept. Batr., pp. 64-65, 1890; Cope, Ann. Rept. U. S. Nat. Mus., 1898, p. 336, 1900; Dunn, Proc. Acad. Nat. Sci. Phila., 88, p. 474, 1936; Smith, Proc. Biol. Soc. Wash., 49, p. 95, 1936. Sceloporus acanthinus Gunther, Biol. Cent.-Amer., Rept. Batr., pp. 65-66, 1890 (part); Duges, Naturaleza, (2), 2, p. 480, 1896; Gadow, Proc. Zool. Soc. Lond., 2, pp. 194, 214, 231, 232, 1905; idem, Through Southern Mexico, pp. 270, 513, 1908; idem, Zool. Jahrb., Syst., 29, p. 706, 1910; Ahl, Zool. Anz., 106, p. 184, 1934. Sceloporus formosus formosus Wettstein, Sitzber. Akad. Wiss. Wien, Math. Nat. Kl., 143, Abt. 1, p. 25, 1934. . Type locality. Mexico. Distribution. Mountains of Guerrero and Oaxaca south of the Balsas River; also central western Vera Cruz (fig. 5). Diagnosis. A Sceloporus of moderate size, maximum snout- vent measurement 88 mm.; a pair of black shoulder spots, each with a narrow dorsal extension which fails to meet its fellow by five to six scale rows; dorsal scales average 34; ventral scales average 46; scales around body average 39; femoral pores average 16; median frontonasal in contact with lateral frontonasals; internasal area covered with relatively large scales, usually arranged in one, two, or three pairs; supraoculars small, in one or two rows; usually two, rarely one, canthal, the first usually not forced above canthal ridge; frontal usually in contact with interparietal ; usually one loreal; throat bluish or orange or both; sides of belly blue, black-bordered, the borders sometimes fusing and the black extending over chest and middle of abdomen; nuchal collar complete ventrally in males; latter usually without a light line down the center of each dorsal scale row (present only in Guerrero specimens). Description. 1 Head scales smooth, more or less pitted, convex; frontal ridges very prominent, enclosing a deep depression; inter- parietal pentagonal, its sides somewhat divergent, two or two and 1 Based chiefly on USNM 46837, male, La Parada, Oaxaca. 36 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 one-half times as large as either parietal ; one large parietal, frequently followed posteriorly by a small, elongate scale which might be con- sidered a second parietal; usually one, occasionally two frontoparietals on each side, usually separated medially by contact of frontal and interparietal; frontal typically divided; five or six supra- oculars; usually one to four small scales in a second, outer row of supraoculars; one to three supraoculars of the inner row may contact median head scales; one complete and another incomplete row of FIG. 5. Distribution of Sceloporus asper, mosus, V- ; S. salvini, O; S. formosus for- small scales between supraoculars and superciliaries; usually six, rarely five, superciliaries, five (occasionally four) visible from above; prefrontals usually in contact medially, frequently separated by an azygous scale or by contact of frontal and median frontonasal; frontonasals typical; one or two pairs of internasals, the scales occasionally irregular; four, rarely two, postrostrals; subnasal large; usually two canthals, rarely one; when two canthals are present, the first is seldom above the canthal ridge (second canthal in contact with subnasal); preocular rarely divided; usually one loreal, rarely two or three; two small postoculars; two rows of lorilabials, usually reduced to one row below subocular by contact of one or more 1939 MEXICAN LIZARDS SMITH 37 scales with both subocular and supralabials; three and one-half supralabials and five infralabials to a point below middle of eye. Mental pentagonal, with a labial border slightly more than half that of rostral; about four pairs of postmentals, the scales of the anterior pair in contact medially; outer row of labiomental scales separated anteriorly from mental by partial contact of first post- mental and first infralabial; gular scales immediately below ear keeled, mucronate, denticulate; other gular scales notched, the anterior scales with a single apical notch, the posterior with two apical notches; scales in gular fold area with two apical notches. Auricular lobules smooth, short, about four or five in number, more or less subequal in size, the upper and lower scales pointed, the median scales rounded, the largest extending about half the distance across ear opening, subequal in size to preceding scales; temporal scales weakly keeled, weakly mucronate, denticulate, decreasing in size anteriorly, the largest scales somewhat smaller than scales between ear and lateral nuchal pocket; latter scales strongly keeled, mucronate and denticulate, larger than scales between nuchal pocket and arm; the latter scales weakly keeled, strongly mucronate and denticulate. Dorsal scales 31 to 37, keeled, rather strongly mucronate, denti- culate, in more or less parallel rows; lateral scales subequal in size to dorsal scales, similar in general character, in oblique rows; ventral scales smooth, notched or rounded, those in midventral line some- what smaller than lateral scales; preanal and interfemoral scales subequal in size to middle abdominal scales; scales around body 34 to 43; ventral scales 41 to 54. Dorsal scales on foreleg strongly keeled, strongly mucronate, weakly denticulate, those on upper foreleg about two-thirds size of dorsals on body and somewhat larger than dorsal scales of lower foreleg; ventral scales of lower foreleg keeled, mucronate, denticulate, very slightly smaller than dorsal scales of same member; scales on anterior surface of lower foreleg smooth, somewhat larger than other scales of same member; ventral scales of upper foreleg smooth medially, notched, about one-third size of ventral scales of lower foreleg; lamellar formula for fingers 10-14-18-17-13 (occasionally 19-18 on the third and fourth). Dorsal scales of hind leg strongly keeled, strongly mucronate, weakly denticulate, more or less subequal in size, about two-thirds to three-fourths size of dorsal body scales; scales on ventral surfaces of thigh smooth, rounded, or notched, becoming smaller toward 38 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 femoral pore series, larger toward anterior face of thigh; scales on posterior surface of thigh keeled, mucronate, about one-half size of preanal scales; ventral scales on shank smooth or very faintly keeled, notched or denticulate, subequal in size to dorsal scales of same member; femoral pores 13 to 20; lamellar formula for toes 9-14-19- 21-16 (9-13-18-21-15). Dorsal caudal scales very strongly keeled, strongly mucronate, weakly denticulate, somewhat larger than dorsal scales on body; subcaudals pointed and smooth near base of tail, becoming keeled and mucronate distally; enlarged postanals present in males; no postfemoral dermal pocket. Color. Males with dorsal surfaces iridescent, light olive-green or blue-olive, head drab; a prominent black spot on shoulder, widely separated medially (five or six scale rows), uniting across throat; a somewhat broader band of cobalt blue on ventral surface anterior to black throat band; anterior to this a broad area of light orange (in some specimens the orange is absent, and blue covers the entire area anterior to the black gular collar); sides of belly iridescent, pearl blue, bordered medially by a blue or black band, which band expands posteriorly in the region of the groin; chest and middle of belly white, or, in large males, strongly suffused with black, confluent with black gular collar; ventral surfaces of tail white, suffused more or less with pale blue in large males. In females the dorsal color is brown or brown-olive; the black marks on the shoulders are narrower than in males and extend farther dorsally (separated by two or three scale rows) ; two parallel dark lines, sometimes broken and usually indistinct, pass from the upper edge of the scapular mark onto the tail; on the sides of body and on the neck are scattered indistinct dark spots; the belly is immaculate, suffused slightly with blue in some specimens. Variation. The variation of the head scales in 51 specimens is as follows: parietals one or two (78 counts: 1, seven; 2, seventy-one); frontoparietals one or two on each side (1, eighty-five; 2, seventeen); frontal contacts interparietal in 49, separated by an azygous scale in two; frontal entire in one, the posterior section divided into three in one (39 examined); superciliaries five or six (5, four; 6, seventy- four); supraoculars in one or two rows, irregular; one or more sup- raoculars in contact with median head scales in 11 specimens; prefrontals in contact medially in 27, separated by an azygous scale in 11, by contact of frontal and median frontonasal in 13; fronto- nasals normal in all; internasals rather irregular, usually in one or 1939 MEXICAN LIZARDS SMITH 39 two pairs; subnasal present in all; one canthal in five (fused with subnasal in two of these), two in 97; first canthal forced above canthal ridge by contact of second canthal and subnasal in 15; pre- ocular divided in 6, entire in 96; one to three loreals (1, sixty-seven; 2, eight; 3, three); postrostrals two or four (2, two; 4, thirty-seven); two rows of lorilabials in all, reduced to one row below subocular by contact of one or more scales with both subocular and supralabials on one side in 3, on both sides in 35. Dorsal scales 31 to 37, average 34 (52 counts: 31, two; 32, eight; 33, eleven; 34, ten; 35, eleven; 36, six; 37, four); ventral scales 39 to 54, average 46.6 (51 counts: 39, one; 41, three; 42, four; 43, two; 44, five; 45, five; 46, four; 47, eight; 48, two; 49, four; 50, four; 51, four; 52, three; 53, one; 54, one); scales around body 34 to 43, average 39.3 (51 counts: 34, two; 35, one; 36, two; 37, five; 38, four; 39, nine; 40, ten; 41, eight; 42, five; 43, five). Femoral pores 13 to 20, average 15.9 (98 counts: 13, one; 14, sixteen; 15, twenty; 16, thirty-one; 17, twenty; 18, seven; 19, two; 20, one). Geographic variation. Specimens from Guerrero (Chilpancingo, Omilteme) differ from the Oaxacan and Vera Cruzian /. formosus as follows: males with a light blue line down each dorsal scale row; large, well-defined, white or pinkish spots on the head in both sexes one on each parietal, on the interparietal, posterior section of frontal, both prefrontals, lateral frontonasals, posterior pair of internasals, and on several of the supraoculars and superciliaries. One male specimen from Omilteme (MCZ) differs from others from the same locality in lacking the light spots on the head and the light lines on the body, and in having much smaller scales on the posterior surface of the thigh, and smaller dorsal scales (40 from occiput to base of tail). A male specimen (AMNH 58261) from Tlaxiaco, Oaxaca, while typical in scutellation, shows a rather aberrant coloration, at least in that sex at its size (67.4 mm. snout- vent). Its coloration is as follows (from the freshly preserved specimen) : a light brownish gray, median dorsal band one and two half scale rows wide, extending from nape onto tail; a bluish green band on either side of this, two and two half scale rows wide at middle of body, narrower anteriorly and posteriorly; latter bands end at base of tail; a dorsolateral light band one scale row wide extending from nape onto tail; sides of body bluish green, with a faintly visible, whitish lateral stripe; sides of chest, gular fold region, and shoulder area black; shoulder spot bordered posteriorly by a narrow light line yellow medially and pale 40 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 bluish at extremities; a light, longitudinal line on posterior surface of thigh, bordered above and below by a narrow dark line; toes, hands, and fingers darker than other parts of limbs; limbs not barred or otherwise marked, except thigh with a few dark spots on anterior surface; posterior part of throat dark blue, anterior part apparently yellowish or light orange; sides of abdomen light cerulean blue, bordered medially by dark blue, followed medially by a narrow area of black; a small black spot in groin; a whitish median abdominal band three to four scales wide, and another across chest between axillae two scales wide. Remarks. A number of authors, probably influenced by Cope, have incorrectly interpreted Wiegmann's Sceloporus formosus. Cope thought the name applied to a broad-collared form, of which he had several specimens from Jalapa. He therefore described the common Mexican species as viviparus, a form actually synonymous with Wiegmann's formosus. The form which Cope thought was formosus was actually not described until 1890, when Giinther named it salvini, based upon specimens from Guatemala, southern Mexico, and Jalapa. As the Guatemalan cotypes probably are the same as Bocourt's smaragdinus, and the southern Mexico cotypes of doubtful identity, I designate the single Jalapa cotype (specimen o, male, in Boulenger's table, 1897, p. 503) as the lectotype of salvini, thereby making the name available for the species redescribed below under that name. For determination of the identity of Wiegmann's/ormosws I have relied upon Bocourt's redescription and figures, which were based upon Wiegmann's type (1874). In the figure, two characters of im- portance are to be noted: there are two pairs of internasals, and the median frontonasal is in contact with the lateral frontonasals. The condition of these scales is similar in the types of viviparus, except that the internasals are not always in two pairs; in salvini the internasal area is quite different, covered by a relatively large number of highly irregular, small scales; the median frontonasal is always separated from the lateral frontonasals. In his description of formosus Bocourt states that each of the shoulder spots has a narrow dorsal extension toward the middle of the neck, failing to meet the opposite mark. The spots are similar in the supposed viviparus, while in salvini a broad nuchal collar is present, complete or abruptly broken medially by a narrow area about one scale row wide. Habits and habitat. The species is largely confined to high eleva- tions. Gadow (1910) states that it occurs at elevations from 500 1939 MEXICAN LIZARDS SMITH 41 feet to 9,000 feet. I very much doubt that it descends as low as 500 feet. It seems to be entirely arboreal, and shows a preference for pine forests, avoiding tropical or subtropical deciduous forests and areas covered by the smaller cedar trees. In areas in which I have observed the species, individuals are seen during a short period during the middle of the day (from about 10:00 A.M. to 4:00 P.M.), and numerous, cloudy days pass which are too cool to permit their emergence. In life the males are most brilliantly and beautifully colored, and are easily discerned at a distance. Females are more difficult to see, being darker, but they are much more easily captured. Females may be caught by hand by carefully stalking them; males cannot, so far as I observed. As recorded by numerous authors (first by Sumichrast, 1864), /. formosus is ovoviviparous. Locality records. VERA CRUZ: Xuchil (FMNH 1521[12]); 1^-2 mi. W of Acultzingo (EHT 8672-7); Orizaba (USNM 30209-12, 64670) ; Mirador (USNM 25073). OAXACA: Tlaxiaco, NW of Oaxaca (AMNH 58261); Cerro de San Luis, 15 mi. N of Oaxaca (EHT 8661-71) ; Cerro de San Felipe (USNM 47387) ; Tehuantepec (USNM 30128); Reyes (USNM 47393-4, 47368); Mt. Zempoaltepec (USNM 47406-11); Mts. W of Oaxaca (USNM 47378-9); Totontepec (USNM 46675, 46677); La Parada (USNM 46837); San Pedro Alta (AMNH 18375-89); San Pedro, San Miguel, San Jose" and valley of Miahuatlan (AMNH 18706-19). GUERRERO: Omilteme (MCZ 28655, and 5 without number) ; Chilpancingo (MCZ 33879) ; Xochitempa, near Chilapa (Ahl, 1934). Gadow (1905) records the species from the Nevado de Colima, Jalisco; Bocourt (1874) records it from "Colima." I doubt these records. Sceloporus formosus smaragdinus Bocourt. 1 Sceloporus smaragdinus Bocourt, Ann. Sci. Nat., Zool., (5), 17, No. 10, p. 1, 1873; idem, Miss. Sci. Mex., Zool., 3, sec. 1, pp. 186-188, pi. 18, figs. 6, 66, pi. 19, figs. 1,16, 1874; Gtinther, Biol. Cent.-Amer., Kept. Batr., pp. 68-69, 1890 (part); Wettstein, Sitzber. Akad. Wiss. Wien., Math.-Nat. Kl. f 143, Abt. 1, p. 25, 1934; Smith, Proc. Biol. Soc. Wash., 49, p. 95, 1936. Sceloporus malachiticus Cope, Proc. Amer. Phil. Soc., 22, p. 397, 1885 (part); idem, Bull. U. S. Nat. Mus., 32, p. 36, 1887 (part); Muller, Verb. Naturf. Ges. Basel, 7, p. 712, 1885. 1 It has been difficult to determine the exact identity of material not seen by me which is referred by other authors to various members of the formosus group. Part of the synonymy referred to acanthinus may belong under this subspecies. 42 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 Sceloporus taeniocnemis Cope, Proc. Amer. Phil. Soc., 22, p. 399, 1885 Guatemala (type, USNM 24768, collected by H. Hague); idem, Bull. U. S. Nat. Mus., 32, p. 37, 1887; idem, Ann. Kept. U. S. Nat. Mus., 1898, p. 336, 1900; Smith, Proc. Biol. Soc. Wash., 49, p. 95, 1936. Sceloporus salvini Giinther, Biol. Cent.-Amer., Kept. Batr., p. 68, 1890 (part). Sceloporus formosus Werner, Abh. Bayer. Akad. Wiss., Math.-Phys. Kl., 22, Abt. 2, p. 344, 1903 (part); Boulenger, Proc. Zool. Soc. Lond., 1897, pp. 501-503, 1897. Sceloporus schmidti Jones, Occ. Papers Mus. Zool. Univ. Mich., 186, pp. 4-7, 1927 Mountain Camp west of San Pedro, Honduras, 4,500 ft. (type lost); Schmidt, Field Mus. Nat. Hist., Zool. Ser., 20, p. 15, 1933; Smith, Proc. Biol. Soc. Wash., 49, p. 95, 1936. Type locality. Guatemala, in the vicinity of Solola, Totonica- pam, and Quetzaltenango. Paratype USNM 11000. Distribution. Plateau of Chiapas, southward and eastward on the plateau of Guatemala, including the Coban region, to El Salva- dor, and northward in western Honduras (fig. 6). Diagnosis. Similar to S. formosus malachiticus, differing in maximum size, size of body scales and in coloration of the male; FIG. 6. Distribution of the Central American species of the formosus group: Sceloporus formosus smaragdinus, O; S. f. malachiticus, A. 1939 MEXICAN LIZARDS SMITH 43 maximum snout- vent measurement 85 mm.; dorsal scales 38 to 49, average 43; ventral scales 45 to 55, average 50; scales around body 41 to 52, average 48; femoral pores 11 to 18, average 15; frontal seldom separated from interparietal; supraoculars in two irregular rows; one canthal or, if two, the first usually forced above canthal ridge by contact of second canthal and subnasal ; loreal very irregu- lar, usually fused with other scales or divided into two or more scales; anterior part of gular region usually orange or red-orange in males; dorsal surfaces of males lined as in /. malachiticus; females colored as in the latter; shoulder spots in males with a narrow dorsal extension not reaching the mid-dorsal line. Color. In preserved males: greenish blue to blue-olive above; a narrow dark streak down the side of each dorsal scale row; toes and fingers faintly barred; a large black spot in front of each shoulder, the two separated from each other by about nine scale rows; scales cyanine blue (shed); most of scales on head with a light central area; tail faintly barred; two irregular parallel dark lines on pos- terior surface of thighs, separated from each other by a narrow white line. Posterior part of throat cyanine blue, fading anteriorly on chin and in labial regions to an olive-blue; a broad black band across gular fold region, continuous with black shoulder spots; chest usually dusky white, sometimes black (largest males); sides of abdomen cyanine blue, sometimes darker; lateral abdominal areas with a black median border, the two borders usually separated by a median longitudinal white band, sometimes nearly meeting medially, or separated by a very dark gray area; groin cyanine blue, never black; ventral surfaces of limbs greenish blue. A series of about eleven small dark spots on each side of back in females; these spots very irregular in shape, sometimes rounded, sometimes narrow and appearing as short transverse bands; limbs fairly distinctly banded or mottled with black; sides of abdomen with irregular dark marks, tending to be arranged in two rows; shoulder spots sometimes narrowly continuous across neck. Ventral surfaces greenish blue, immaculate. In both sexes the shoulder spots usually have a light posterior border. Variation. Variation in cephalic scutellation of 61 specimens has been recorded. Parietals one to three on each side (1, twenty-seven; 2, ninety-four; 3, one); frontoparietals one or two (1, one hundred and ten ; 2, eight) ; frontal in contact with interparietal in 50, separated 44 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 by an azygous scale in none, by contact of frontoparietals in 11; pos- terior section of frontal transversely divided in one; frontal entire in one; superciliaries five to seven (5, one; 6, one hundred and fourteen; 7, seven); supraoculars in two series, the outer series consisting of one to seven scales (average four) ; four to six scales in inner row of supraoculars (4, thirty-nine; 5, seventy- three; 6, ten); one or more supraoculars contact median head scales in three; prefrontals in contact medially in 23, separated by an azygous scale in eight, by contact of frontal with median frontonasal in 29; frontonasals irregular in two, normal in others; one to three pairs of internasals, or a combination of these, or somewhat irregular; subnasal present in all; two canthals, the first not forced above canthal ridge on one side in two, on both sides in four; one canthal or, if two, the first forced above canthal ridge by contact of second canthal and sub- nasal in the remainder; preocular divided on one side in one, on both sides in 12; loreals none to five (0, seven; 1, fifty; 2, thirty- eight; 3, twenty-one; 4, five; 5, one); postrostrals two to four (2, seven; 3, four; 4, forty-nine); two rows of lorilabials, reduced to one row below subocular by contact of one or more scales with both subocular and supralabials on one side in seven, on both sides in twenty-eight. Dorsal scales 38 to 49, average 42.8 (75 counts: 38, two; 39, two; 40, eight; 41, fourteen; 42, twelve; 43, eight; 44, ten; 45, nine; 46, five; 47, two; 48, one; 49, two); ventral scales 45 to 55, average 50.2 (60 counts: 45, one; 46, two; 47, three; 48, four; 49, thirteen; 50, nine; 51, thirteen; 52, nine; 53, two; 54, three; 55, one); scales around body 41 to 52, average 47.5 (61 counts: 41, one; 43, two; 44, four; 45, four; 46, six; 47, fifteen; 48, seven; 49, ten; 50, eight; 51, two; 52, two). Femoral pores 11 to 18, average 15 (127 counts: 11, one; 12, four; 13, eight; 14, thirty-five; 15, thirty-six; 16, twenty- four; 17, sixteen; 18, three). Geographic variation. The available specimens associated with this subspecies are relatively constant in scale characters and colora- tion. A few specimens deserve comment. Three from Coban differ from the typical in having 38, 39, and 42 scales from occiput to base of tail. The lowest of these is the lowest observed in the entire series of this subspecies. The femoral pores in two of these speci- mens are 12-12, 12-12; the ventrals 42, 40; the scales around body 44, 42. All counts are extremely low for /. smaragdinus. Eight specimens from the Volcan Tajumulco, Guatemala, are somewhat different from others of /. smaragdinus. These differences 1939 MEXICAN LIZARDS SMITH 45 are as follows: dorsal scale count averages slightly higher; femoral pore count averages slightly lower; lesser maximum size (64 mm. snout- vent) ; males with spots on back like females, and with exten- sions of the black shoulder patches, which are separated on the neck by only two or three scale rows; nuchal collar two scales wide on sides of neck; belly completely cyanine blue, lighter in middle; black medial border of belly patches not extending into groin or onto chest; throat lighter blue than belly; lower surfaces of limbs pearl blue; tail suffused ventrally with cyanine blue; females tend to have the spots on back narrower, the collar on neck narrower. I believe these specimens demonstrate a phenomenon first observed by Wettstein (1934). This author showed that decrease in maxi- mum size and loss of sexual dichromatism occurs in /. malachiticus at high elevations and low average temperatures. The same appears to be true of /. smaragdinus. Remarks. S. schmidti is clearly the same as /. smaragdinus, having 42 dorsal scales; S. taeniocnemis is definitely identical, hav- ing 12 scales to the head length and other characters of /. smarag- dinus. S. salvini Giinther is a composite of at least two species, part of the cotypes coming from Guatemala, the others from Jalapa. I consider that his Guatemalan specimens are /. smaragdinus (fide data given by Boulenger, 1897). Habits and habitat. A number of specimens, from Chichivac, Tajumulco, and Coban, Guatemala, collected in February and March, have young in the abdomen. Slevin states that /. smarag- dinus is common on rock fences, occasionally is found on trees. Locality records. CHIAPAS: Pinobete (USNM 47761-3) ; Teopisca (USNM 47503). GUATEMALA: (USNM 24768; ANSP 8485; UMMZ 67690 [4]): Todos Santos (USNM 47521-2); Chancol (USNM 47514-5); San Lucas Volcano (UMMZ 71764[2], 71766[6]; MCZ 28121-50; SDSNH 16308); 5 mi. N of Tecpan, Chimaltenango (CAS 68291-68345); Tecpan (MCZ 28107-11); San Mateo (MCZ 28117-8); Panajachel (MCZ 28112-3); Barrillos (MCZ 28119); La Perla (MCZ 28120); Volcan Agua (FMNH 20290; CAS 68219-35); Coban (FMNH 20533, 21003; ANSP 11316); Santa Elena, Chi- maltenango (FMNH 20221-5, 20238; CAS 68392-3); Chichivac, Chimaltenango (FMNH 20255[34], 20276, 20279[38]); Atitlan (FMNH 2053) ; Sierra Santa Elena, near Tecpan, 9,500 ft. (FMNH 1925[8]),' Volcan Tajumulco/ San Marcos, 10,500 to 13,400 ft. 46 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 (FMNH 20311-6, 20698-9); San Antonio, Sacatepequez (CAS 68236-90). HONDURAS: Mts. west of San Pedro (Jones, 1927). Sceloporus formosus malachiticus Cope. Sceloporus malachiticus Cope, Proc. Acad. Nat. Sci. Phila., 1864, p. 178, 1864; idem, 1871, p. 205, 1871; idem, Jour. Acad. Nat. Sci. Phila., (2), 8, pp. 95, 127, 1876; Sumichrast, Naturaleza, 6, p. 38, 1882 (part); Cope, Proc. Amer. Phil. Soc., 22, p. 397, 1885 (part); idem, Bull. U. S. Nat. Mus., 32, p. 36, 1887 (part); idem, Ann. Kept. U. S. Nat. Mus., 1898, p. 335, 1900; Schmidt, Field Mus. Nat. Hist., Zool. Ser., 12, pp. 193, 196, 1928; Dunn and Emlen, Proc. Acad. Nat. Sci. Phila., 84, p. 28, 1932; Smith, Proc. Biol. Soc. Wash., 49, p. 95, 1936. Sceloporus formosus Boulenger, Cat. Liz. Brit. Mus., 2, pp. 217, 222-223, 1885 (part); Boettger, Kat. Kept. Senck. Mus., p. 64, 1893 (part); Bou- lenger, Proc. Zool. Soc. Lond., 1897, pp. 501-503, fig. 3, 1897 (part). Sceloporus irazuensis Gtinther, Biol. Cent.-Amer., Kept. Batr., pp. 67-68, 1890 (part) Irazu, Costa Rica; Wettstein, Sitzber. Akad. Wiss. Wien, Math.-Nat. Kl., 143, Abt. 1, p. 25, 1934; Smith, Proc. Biol. Soc. Wash., 49, p. 95, 1936. Sceloporus formosus malachiticus Wettstein, Sitzber. Akad. Wiss. Wien, Math.-Nat. Kl., 143, Abt. 1, pp. 24-25, 28, 1934. Type locality. Upper Costa Rica. Type USNM 12186, col- lected by C. H. Riotte. Distribution. El Salvador and central Honduras to western Panama (fig. 6). Diagnosis. A Sceloporus of moderate size, maximum snout- vent measurement 91 mm. ; a black shoulder spot present, lacking a narrow dorsal extension; dorsal scales 30 to 39, average 35; scales around body 30 to 45, average 37.9; ventral scales 36 to 46, average 42.2; femoral pores 11 to 17, average 14.3; frontal usually separated from interparietal; supraoculars in two irregular series; one or more supraoculars very frequently in contact with median head scales; one canthal or, if two, the first usually forced above can- thai ridge; males usually with a light line down the center of each dorsal scale row. Description. 1 Head scales smooth, weakly convex, pitted; inter- parietal large, pentagonal, about two-thirds size of supraorbital area, about five times as large as either parietal; frontoparietals rarely divided; frontal in contact with interparietal or not; frontal normal; supraoculars four to six (inner row), usually five, these rarely entire, usually one or more scales divided, forming an outer row of 1 Based mainly on UMMZ 71997, Santa Maria, Costa Rica. 1939 MEXICAN LIZARDS SMITH 47 smaller supraoculars; one row of small scales between supraoculars and median head scales, frequently incomplete, permitting one or more of the supraoculars to contact median head scales; one com- plete and another incomplete row of small scales between supra- oculars and superciliaries; latter six, five usually visible from above; prefrontals in contact or not; frontonasals typical; nasal separated from rostral; internasals irregular; postrostrals irregular, usually four, frequently three or two (according to locality); usually one apparent canthal (in reality, usually two, but the first small and appearing in scales behind nasal); subnasal large, always present; preocular rarely divided; usually one loreal; usually two rows of lorilabials, rarely one, usually reduced to one row below subocular by contact of one or more scales with both subocular and supra- labials; about four supralabials and five infralabials to a point below middle of eye. Mental pentagonal, with a labial border about two-thirds that of rostral; about five or six pairs of postmentals, the scales of the anterior pair in contact medially; anterior scale of outer row of labiomentals narrowly separated from mental by partial contact of first postmental and first infralabial; gular scales smooth, single, notched, mucronate, and keeled immediately below ear. Auricular lobules small, smooth, mucronate, smaller than preceding scales (occasionally subequal); temporal scales keeled, mucronate, weakly denticulate, the anterior scales smallest, the posterior scales subequal in size to largest scales between ear and nuchal fold; latter strongly keeled, strongly mucronate; a series of enlarged, strongly keeled, strongly mucronate scales extending from middle of nuchal fold to lower margin Of ear; scales between nuchal pocket and arm subequal in size, keeled, strongly mucronate, denticulate. Dorsal scales keeled, strongly mucronate, weakly denticulate, in weakly convergent rows; lateral scales about three-fourths size of dorsal scales, more strongly mucronate and denticulate; ventral scales smooth, each with a single apical notch, about one-half or one- third size of dorsal scales; interfemoral scales somewhat smaller than preanal scales, which are subequal in size to ventral abdominal scales; anterior preanal scales notched, posterior scales entire. Dorsal scales of foreleg keeled, denticulate, mucronate, those on upper foreleg more strongly mucronate, about two-thirds size of dorsal scales on body, and somewhat larger than dorsal scales of lower foreleg; ventral scales of lower foreleg notched, smooth except 48 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 those on anteroventral surface and near hand, which are keeled; scales on ventral surface of upper foreleg smooth, notched, about one-half or one-third size of ventral scales of lower foreleg; lamellar formula for toes 9-13-17-19-13 (8-13-15-18-13). Dorsal scales of hind leg keeled, rather strongly mucronate, weakly denticulate, subequal in size (the largest scales of either member), about two-thirds size of dorsal scales on body; scales on anterior surface of thigh smooth or weakly keeled, mucronate and denticulate, becoming notched, smooth and smaller on ventral sur- face; scales on posterior surface of thigh keeled, mucronate, the largest somewhat smaller than preanal scales; ventral scales on shank smooth, notched, nearly as large as dorsal scales of same member; lamellar formula for toes 8-12-19-20-14 (8-13-18-20-14). Dorsal caudal scales strongly keeled, strongly mucronate, some- what larger than dorsal scales on body; subcaudals smooth and with two apical notches at base of tail, becoming keeled and mucronate distally (both sexes); enlarged postanals present in males; no post- femoral dermal pocket. Color. General ground color in males malachite blue, olive green or olive brown; each dorsal scale row with a broad median lighter streak; these lighter lines separated from each other by nar- row dark lines occupying the edges of two adjacent scale rows; limbs apparently with faint, darker bands; toes and fingers barred rather distinctly; tail with faint alternating dark and light bars. Throat bluish, becoming darker posteriorly; gular fold region black, this color extending onto shoulder, but not onto back; sides of belly blue, with a dark blue or black median border, the two separated by four or five scale rows, this border not extending onto chest or into groin; chest, a band down middle of belly, and ventral surfaces of limbs and tail, immaculate, suffused with light blue (in some specimens, chest rather heavily suffused with black). Females tend to be darker-colored above; both young and old females usually show four or six rows of large, rather sharply out- lined, brown-black spots on the back, of which the two median con- tinue onto the tail (Wettstein, 1934); the nuchal collar is fairly distinct, and complete in the young; throat and sides of belly bluish (apparently; in preservative these areas appear dark); remainder of belly dusky white. The rows of dorsal spots are sometimes variously modified; in some, one or more rows have the individual spots fused to form 1939 MEXICAN LIZARDS SMITH 49 indistinct irregular stripes; the sides of the abdomen frequently have irregular indistinct darker and lighter areas. Wettstein (1934), who had access to Zimara's field notes, states that this subspecies never has the throat colored orange-red, but always bluish. In the preserved material personally examined, this statement appears to be true. Variation. The variation in cephalic scutellation in 61 specimens was noted. Parietals one or two (1, four; 2, one hundred and eight- een) ; frontoparietals one or two (1, one hundred and eleven ; 2, eleven) ; frontal touches interparietal in 27, separated by an azygous scale in two, by contact of frontoparietals in 32; anterior section of frontal longitudinally divided, posterior section transversely divided in one; superciliaries five to seven (5, five; 6, one hundred and ten; 7, seven) ; supraoculars entire in four; four to six scales in inner row of supra- oculars (4, thirty-nine; 5, sixty- three; 6, twenty); one or more supraoculars contact median head scales in 31; prefrontals in con- tact medially in 15, separated by an azygous scale in 24, by contact of frontal with median frontonasal in 22; median frontonasal irregu- larly divided in one specimen, separated from one lateral frontonasal in one; usually two pairs of internasals; subnasal present in all; canthals usually two, occasionally one, the first usually forced above canthal ridge by contact of second canthal and subnasal; preocular divided on one side in one, on both sides in another; loreals none to five (0, seven; 1, ninety-three; 2, twenty; 3, one; 5, one); postrostrals two to five (2, twelve; 3, thirteen; 4, thirty- two; 5, one); two rows of lorilabials, reduced to one row below subocular by con- tact of one or more scales with both subocular and supralabials on one side in 12, on both sides in 29. Dorsal scales 30 to 39, average 35 (75 counts: 30, one; 31, one; 32, five; 33, eleven; 34, twelve; 35, fifteen; 36, ten; 37, twelve; 38, five; 39, three); ventral scales 36 to 46, average 42.2 (61 counts: 36, one; 37, one; 38, four; 39, four; 40, five; 41, four; 42, nine; 43, twelve; 44, ten; 45, eight; 46, three); scales around body 30 to 45, average 37.9 (62 counts: 30, one; 31, one; 32, one; 34, four; 35, five; 36, six; 37, ten; 38, seven; 39, seven; 40, ten; 41, five; 42, two; 43, two; 45, one). Femoral pores 11 to 17, average 14.3 (116 counts: 11, one; 12, seven; 13, twenty-four; 14, thirty-one; 15, twenty-nine; 16, twenty; 17, four). Remarks. Wettstein (1934) states that the higher the elevation and the lower the average temperature the less brilliant the colora- tion and the less the maximum size. At a height of 3,000 meters on 50 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 the Volcan Irazu, Costa Rica, Zimara observed that the specimens were only half as large as those from the lower lakes, and all were so dull colored that the sexes could be distinguished only upon exami- nation at close quarters. Wettstein concludes that Giinther must have based his S. irazuensis on such specimens as these. Specimens collected by Zimara on the high plateau about San Jose", at eleva- tions between 1,100 and 1,500 meters, showed brilliant coloration and obvious sexual dichromatism. Specimens from Panama differ from others of this subspecies in having the frontoparietals broadly in contact (17 specimens, one exception, with an azygous scale between frontoparietals), and in usually having one or more supraoculars in contact with the median head scales (three specimens in 17 have the supraoculars completely separated from the median head scales). There apparently are no other differences accompanying these. Even these minor differences are not sufficiently well established, I believe, to warrant recognition of another race. Specimens from certain localities in Costa Rica tend strongly toward the Panama specimens in the condition of the supraoculars, and specimens from Honduras tend strongly toward the Panama specimens in the condition of the frontoparietals. Apparently these characters are subject to much geographical vari- ation, notwithstanding the fact that they may be fairly constant in one locality. Specimens from Salvador show evidence of intergradation with /. smaragdinus, their scale counts being relatively high (dorsal scales: 35, one; 38, two; 39, two. Scales around body: 40, two; 43, two; 45, one). These counts are almost exactly intermediate between those of /. malachiticus and /. smaragdinus. Specimens of this subspecies from Honduras differ somewhat in coloration from the specimens from Salvador, Costa Rica, and Panama. The males show but slight evidence of the typical lined pattern (some show none); the black shoulder patch infrequently extends across the throat; and in females the dorsal surfaces of body and limbs are more distinctly banded and spotted. These apparent color differences may be due in part to manner of preser- vation. It may be noted that Jones' schmidti, from San Pedro, Honduras, does not belong to the /. malachiticus complex, having (according to the description) 42 dorsal scales. I associate it with m. smaragdinus, with which it agrees in coloration and scale counts. Habits and habitat. Specimens from Costa Rica and El Salvador (the former collected in January) contain young in the abdomen. 1939 MEXICAN LIZARDS SMITH 51 Nothing seems to have been published upon the habitat of this subspecies. Mrs. H. T. Gaige informs me that specimens observed in Panama occurred at an elevation of about 4,500 feet on boulders and fallen logs in relatively open areas. Locality records. EL SALVADOR: Los Esemiles, Chalatenango (FMNH 10958-62). HONDURAS: (MCZ 9515-6) ; Portillo Grande, Yoro (FMNH 21872- 5; MCZ 38851-4); Subirana Valley, Yoro (FMNH 21793; MCZ 38846-7[4]; UMMZ 77844[2]); Subirana Ranch (MCZ 38848-50, 32283-92; UMMZ 71289[10j); Mataderos Mts. (MCZ 38845[2]); San Juancito (Dunn and Emlen, 1932). NICARAGUA: (MCZ 13890-1); Bluefields (AMNH 16234-5); Ocotal Pinelands (MCZ 9590-1). COSTA RICA: San Jose" (FMNH 2477-8(7]; AMNH 16324, 16326-25; ANSP 8487; CAS 54643-4; USNM 13540, 13543, 37500- 3, 38689, 73529, 74513, 75439); Tablazo (ERD 8); Carpintera (ERD 3); Rio Virilla (ERD 1); Tilaran (ERD 1); Santa Clara (AMNH 16325); between Cartago and Agua Caliente (MCZ 32179); Esparta (MCZ 19134-5); Irazu (MCZ 20495-7, 15368-73); El Copey (MCZ 28075) ; La Estrella (MCZ 28074) ; Barba (MCZ 28076) ; Navarro (MCZ 15356-65; UMMZ 71765[2]); Rio Navarro, 4,000 ft. (UMMZ 74296-7(3]); Liberia, Guanacaste, 800 ft. (UMMZ 71995[2]); Har, 3,200 ft., Santa Maria, Guanacaste (UMMZ 71997 [6]); Alajuela (USNM 37504); Cartago (USNM 69453-4); Punta- renas, San Jose" (USNM 73392); Upper Costa Rica (USNM 12186, 101062-5); San Isidro de Coronado, Hda. Guayabillos (Irazu, 2,200 meters), Hda. Chicua (Irazu, 2,800 meters), Orosi (Irazu) (Wett- stein, 1934). PANAMA: Above Boquete, Chiriqui (MCZ 31698-9); Quiel, dis- trict Boquete, Chiriqui (MCZ 34280); Boquete, Chiriqui (UMMZ 58016-8, 58020^, 58026-36; USNM 51975). Sceloporus asper Boulenger. Sceloporus asper Boulenger, Proc. Zool. Soc. Lond., 1897, pp. 476, 497-498, pi. 33 (colored), 1897; idem, 1898, p. 915, 1898; Gadow, Proc. Zool. Soc. Lond., 2, p. 232, 1905; Ahl, Zool. Anz., 106, p. 184, 1934. Sceloporus obscurus Van Denburgh, Proc. Acad. Nat. Sci. Phila., 1897, p. 462, 1898 Tepic, Nayarit (type, CAS 3213, collected by Gustav Eisen). Type locality. La Cumbre de los Arrastrados, Jalisco. Distribution. Mountainous regions of western Mexico from Nayarit to Guerrero (fig. 5). 52 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 Diagnosis. A Sceloporus of moderate size, maximum snout- vent measurement 81 mm.; shoulder spot faint; scales on posterior surface of thigh about two- thirds size of preanal scales; dorsal scales 29 to 35, average 33.3; ventral scales 45 to 56, average 50.3; scales around body 40 to 48, average 43.7; femoral pores 15 to 19, average 16.8; dorsal scales strongly keeled, strongly mucronate; largest median lateral scales two- thirds size of dorsal scales; ventral scales one-fourth size of dorsal scales; supraoculars irregular; two canthals; anterior section of frontal usually longitudinally divided. Gular region of males immaculate; sides of belly pale blue, not dark- bordered; middle of abdomen light. Description. 1 Head scales rather strongly convex, smooth, pit- ted; interparietal sub triangular, about three and one-half times as large as either parietal; parietals single on each side; fronto- parietals one or two on each side; frontal in contact with inter- parietal; anterior section of frontal usually longitudinally divided; two rows of supraoculars, the scales of the outer row much smaller than those of the inner row; one row of small scales separating supraoculars from median head scales, and another separating them from superciliaries; usually six or seven superciliaries, five or six visible from above; pref rentals usually separated medially by an azygous scale; frontal ridges distinct, enclosing a distinct depression between; frontonasals typical; internasals more or less irregular; nasal separated from rostral; normally four postrostrals; subnasal large; two canthals typical; usually one loreal; preocular frequently divided; usually two distinct rows of lorilabials, one row occasionally nearly obsolete; two postoculars; three and one-half to four and one- half supralabials, and five or six infralabials to a point below middle of eye. Mental triangular, with a labial border slightly less than half that of rostral; five or six pairs of postmentals, the scales of the first pair narrowly separated medially, the scales of the other pairs widely separated; posterior median gular scales weakly notched; gular scales very weakly striated, those toward sides of neck keeled, strongly mucronate. Auricular lobules short, about four in number, the lower ones distinctly keeled, all smaller than preceding scales; temporal scales keeled, not mucronate, much smaller anteriorly than posteriorly, the largest larger than scales between ear and lateral nuchal pocket; a row of enlarged, very strongly keeled, strongly mucronate scales 1 Based mainly on EHT 8678A, female, Uruapan, Michoacan. 1939 MEXICAN LIZARDS SMITH 53 extending from upper end of nuchal fold to lower edge of ear; of the scales between nuchal pocket and arm, the upper ones largest, most strongly keeled, and weakly denticulate, the lower of these scales somewhat smaller, less strongly keeled, the scales between these two groups of scales separated from each other by a group of considerably smaller scales. Dorsal scales strongly keeled, strongly mucronate, not denticulate, in slightly oblique rows, those on neck most strongly keeled; lat- eral scales less strongly keeled than dorsals, very weakly denticulate, about two-thirds size of dorsal scales; ventral scales smooth, notched, about one-fourth size of dorsal scales; interfemoral scales much smaller than preanal or median abdominal scales. Dorsal scales of foreleg keeled, rather strongly mucronate, not denticulate, those on upper foreleg about one-half or three-fifths size of dorsals on body, somewhat larger than those on lower fore- leg; ventral scales of lower foreleg smooth, notched, except those near hand and near anterior surface, which are keeled and mucronate; ventral scales of upper foreleg notched, smooth except toward anterior and posterior surfaces, about one-third size of those of lower foreleg; lamellar formula for fingers 9-14-?-18-13 (9-13-18-18-14). Dorsal scales of hind leg keeled, mucronate, weakly denticulate, those on shank about two-thirds size of dorsals on body, somewhat larger than those on thigh; ventral scales smooth, notched, those near femoral pore series weakly keeled; largest scales on posterior surface of thigh about two-thirds size of preanal scales; ventral scales on shank smooth, pointed, slightly smaller than dorsal scales of same member; lamellar formula for toes 9-14-17-21-15 (8-13-17- 20-16). Dorsal caudal scales slightly larger and more strongly keeled and mucronate than scales on middle of back; subcaudals near base of tail weakly keeled, mucronate, becoming more strongly keeled distally (females); enlarged postanals present in males; no post- femoral dermal pocket. Color. In males, olive or hair brown above, with a decided bluish tinge mid-dorsally; limbs faintly banded with darker brown; tail with narrow very light gray bands; an indistinct black spot in front of shoulder. Belly mixed pale blue and pearl blue, lighter medially; chest, throat, and ventral surfaces of limbs and tail dingy white, with a tinge of blue; region anterior to gular fold tinged with brown or black, with irregular small light flecks; a median ventral, narrow line on the throat is dingy white. 54 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 Females similar to males, except for faint, undulate, darker brown bands, about three in number, extending across back; shoulder spots extending upward, separated from each other medially by about three or four scales; belly dingy white, with a bluish tinge; throat darker than belly, with a narrow, lighter, median ventral band two scales wide. Variation. The variation in the scutellation of the head in 16 specimens is as follows: One parietal in all; frontoparietals one or two (1, twenty; 2, twelve); frontal touches interparietal in all; anterior section of frontal longitudinally divided in 12, transversely divided in one; posterior section of frontal transversely divided in one; frontal normal in two; superciliaries five to seven (5, one; 6, eighteen, 7, thirteen); supraoculars (inner row) four to six (4, five; 5, twenty-two; 6, five); outer row of supraoculars with two to four scales, usually three; prefrontals contact medially in one; frontal contacts median frontonasal in two, separated by an azygous scale in 12; frontonasals irregular in one, the median separated from lateral frontonasals on one side in four, normal in others; inter- nasals more or less irregular, usually paired; subnasal present in all; two canthals in all, the first forced above canthal ridge by contact of second canthal and subnasal on one side in one; preocular divided in six; two loreals on one side in two; three postrostrals in one, four in others; two rows of lorilabials, reduced to one row below sub- ocular by one or more scales in contact with both subocular and supralabials on one side in three, on both sides in nine. Dorsal scales 29 to 35, average 33.3 (16 counts: 29, one; 31, two; 32, one; 33, three; 34, five; 35, four); ventral scales 45 to 56, average 50.3 (16 counts: 45, one; 47, two; 49, three; 50, four; 51, one; 52, one; 53, one; 54, one; 55, one; 56, one); scales around body 40 to 48, average 43.7 (15 counts: 40, one; 41, two; 42, three; 43, three; 44, one; 45, one; 46, one; 47, one; 48, two). Femoral pores 15 to 19 (29 counts: 15, seven; 16, five; 17, seven; 18, nine; 19, one). Habits and habitat. The species definitely tends to avoid heavy woods and small trees. During about ten days of constant collecting at Uruapan, Michoacan, in 1935 and 1936, only two specimens were collected outside of a sparsely forested area described below. After discovery of the first specimen, a day or two after collecting was begun, the species was carefully sought, but only one other speci- men was secured. One of these two was taken at the edge of a heavy forest, sunning itself on the side of a large tree. Along with it were a number of S. m. microlepidotus, whose actions and general 1939 MEXICAN LIZARDS SMITH 55 coloration were remarkably similar. In fact, it was not until after the specimen of asper was shot that it was realized that two species occurred on the trees of that region. The second specimen was discovered on the sunny side of a small tree in an open area. It was not until the last day of my stay at Uruapan that the preferred habitat of asper was discovered. East of the city, near the railroad station, was a sparse forest, consisting of very tall pine trees, where the sun shone on nearly every tree for its full length. Fourteen were collected in two or three hours, together with quan- tities of S. m. microlepidotus. Here, however, the two species could easily be distinguished at a distance. The latter form was less wary, and never ascended to considerable heights in trees. All specimens of asper observed here were sunning themselves high on the tree trunks. It was necessary to sight the specimens at a dis- tance, and approach cautiously to avoid scaring them. All were shot with .22 bullets, as they were beyond the range of .22 shot shells. Collecting was successfully continued until the usual late morning rains started, when the lizards disappeared. Locality records. MiCHOAcAN: Uruapan (EHT 8678A, 8678-92). JALISCO: La Cumbre de los Arrastrados (Boulenger, 1897). GUE- RRERO: Chilap'a (Ahl, 1934). NAYARIT: Tepic (CAS 3213). Sceloporus salvini Giinther. Sceloporus torquatus formosus Cope, Proc. Amer. Phil. Soc., 22, p. 402, 1885; Ferrari-Perez, Proc. U. S. Nat. Mus., 9, p. 193, 1886; Cope, Bull. U. S. Nat. Mus., 32, p. 38, 1887; idem, Ann. Kept. U. S. Nat. Mus., 1898, pp. 340, 349, 1900. Sceloporus formosus Boulenger, Cat. Liz. Brit. Mus., 2, pp. 217, 222-223, 1885 (part); idem, Proc. Zool. Soc. Lond., 1897, pp. 501-503, 1897 (part). Sceloporus salvini Giinther, Biol. Cent.-Amer., Kept. Batr., p. 68, 1890; Wettstein, Sitzber. Akad. Wiss. Wien, Math.-Nat. Kl., 143, Abt. 1, p. 25, 1934; Smith, Proc. Biol. Soc. Wash., 49, p. 95, 1936. Type locality. Jalapa. Lectotype specimen o, male, in Bou- lenger's (1897) table, page 503 (cf. "Remarks," Sceloporus formosus formosus, p. 40). Distribution. Unsatisfactorily known, recorded only from Jalapa, in central-western Vera Cruz and Santo Domingo, Oaxaca (fig. 5). Diagnosis. A moderately large Sceloporus, maximum snout-vent measurement 95 mm.; scales on posterior surface of thigh keeled, mucronate, somewhat more than half size of preanal scales; a com- plete, dorsal nuchal collar three or four scales wide, sometimes abruptly broken medially by a narrow space about the width of 56 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 one scale row; nuchal collar not light-bordered; two regular rows of supraoculars; lateral frontonasals separated from median fronto- nasals; internasals highly irregular, small, numerous; a distinct depression in median prefrontal region, surrounded by ridges; dorsal scales 39 to 44, average 41.2; ventral scales 41 to 50, average 45.1; scales around body 35 to 46, average 42.2; femoral pores 11 to 14, average 12.5. Description. 1 Head scales smooth, pitted; a rather distinct depression in median part of prefrontal area, surrounded by slight ridges; interparietal pentagonal, sides parallel, the scale about three times the size of either parietal; parietal single on either side; one rectangular frontoparietal on each side, the two separated by an azygous scale; frontal typically divided; supraoculars divided, the largest scale of the outer row about two-thirds size of largest scale of inner row; four scales in outer row of supraoculars, six-seven in the inner row; supraoculars separated from median head scales by a single row of small scales, from superciliaries by one complete and another incomplete row of small scales; six superciliaries, five visible from above; pref rentals separated by an azygous scale; median frontonasal subequal in size to, or slightly smaller than, either lateral frontonasal, and separated from latter scales by a small scale on each side; internasals highly irregular; four postrostrals; nasals small, separated from rostral; subnasal large; two canthals, first somewhat smaller than second; one loreal on each side; preocular entire; two postoculars; two rows of lorilabial scales, reduced to one row at a point below subocular by a single scale in contact with both subocular and supralabial scales; four supralabials and five infra- labials to a point below middle of eye. Mental pentagonal, with a labial border about two-thirds that of rostral; four pairs of postmentals, the scales of the anterior pair in contact medially, the others separated; outer row of labiomentals terminating anteriorly with the last scale inserted between the posterior part of the first postmen tal and first infralabial; gular scales below ear pointed, keeled; other gular scales with a single apical notch; scales in gular fold region usually with two, occasionally with three, apical notches. Auricular lobules three on each side, smooth, the upper and lower pointed, the median rounded and twice as large as the others; largest auricular lobule extending about one-half distance across ear opening, slightly larger than preceding scales; temporal scales 1 Based on USNM 6308, Jalapa. 1939 MEXICAN LIZARDS SMITH 57 keeled, mucronate, decreasing in size anteriorly, the largest subequal in size to largest scales between ear and nuchal pocket; scales sur- mounting lateral nuchal fold strongly mucronate; scales between nuchal pocket and arm strongly denticulate, strongly mucronate, keeled, subequal in size to or slightly smaller than largest scales between ear and nuchal pocket. Dorsal scales keeled, mucronate, denticulate, in slightly con- vergent rows, 39 from occiput to base of tail; lateral scales similar to dorsals, more strongly denticulate, in oblique rows, subequal in size to dorsal scales; ventral scales weakly notched, those in mid- ventral line somewhat smaller than lateral ventral scales; midventral scales about three-fourths size of dorsal scales; scales in groin strongly denticulate; scales around body 44; ventral scales 44. Dorsal scales of foreleg keeled, mucronate, those on upper foreleg about two-thirds size of dorsals on body, slightly larger than dorsals of lower foreleg; scales of lower foreleg more or less uniform in size except those on anterior surface; scales on ventral surface of lower foreleg keeled; ventral scales of upper foreleg smooth, notched, about one-half size of ventrals of lower foreleg; lamellar formula for toes 8-13-17-18-13 (9-13-17-19-13). Dorsal scales of hind leg keeled, mucronate, weakly denticulate, subequal in size, about three-fourths size of dorsals on body; ventral scales of thigh smooth, pointed, becoming smaller toward femoral pore series, larger toward anterior surface of thigh; femoral pores 11-13; scales on posterior surface of thigh keeled, mucronate, weakly denticulate, the largest about three-fifths size of preanal scales; ventral scales on shank smooth, pointed, as large as or larger than dorsals on body; lamellar formula for toes 7-12-17-21-16 (7-12-17- 20-15). Dorsal caudal scales very strongly keeled, strongly mucronate, nearly twice as large as dorsals on body; subcaudals keeled except immediately behind anus, mucronate, denticulate; postanals enlarged; no postfemoral dermal pocket. Color. Dorsal ground color dull olive-gray; males apparently with a dark line down the center of each scale row; a broad complete black nuchal collar, narrowly interrupted in the mid-dorsal line in females; a light pineal spot; digits barred; tail with poorly defined undulate dark bands. Infralabial region greenish in males; remainder of gular area pale blue, sometimes with a large medial area pinkish; gular fold region black, the color continuous with that of nuchal collar; chest pale 58 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 lavender in younger specimens, mostly black in the older; sides of belly lavender of varying shades, this color bordered medially by a narrow dark blue band followed medially by a narrow black band; these dark borders not extending into groin; a broad, light band, about four scales wide in center of abdomen, extending posteriorly from posterior part of chest, narrower anteriorly than posteriorly; ventral surfaces of limbs white. Females with a series of about six rounded, indistinctly outlined, dark spots on each side of mid-dorsal line on body, these spots con- tinuing onto tail and coalescing to form bands; two or three irregular rows of spots lateral to the above; limbs faintly barred. Ventral surfaces immaculate. Gular region with a faint bluish suffusion. Variation. The variation in cephalic scutellation of 14 speci- mens is as follows. Parietals one or two (1, twenty-two; 2, six); frontoparietals one or two (1, twenty-five; 2, one); frontal in contact with interparietal in five, separated by an azygous scale in seven, by contact of frontoparietals in one; frontal normal in all; super- ciliaries usually six, seven on one side in one; three to five scales in outer row of supraoculars (3, four; 4, nineteen; 5, five); five to seven scales in inner row of supraoculars (5, eight; 6, sixteen; 7, four); prefrontals separated by an azygous scale in 12, by contact of frontal with median frontonasal in two; median frontonasal separated from lateral frontonasals in all; subnasal present in all; two canthals in all, the first forced above canthal ridge on one side in two, on both sides in seven; preocular partly divided in two; one loreal in all; five postrostrals in one, four in others; two rows of lorilabials, reduced to one row below subocular by contact of one or more scales with both subocular and supralabials on one side in five, on both sides in three. Dorsal scales 39 to 44, average 41.2 (14 counts: 39, two; 40, four; 41, three; 43, four; 44, one); ventral scales 41 to 50, average 45.1 (12 counts: 41, one; 42, one; 43, one; 44, three; 45, two; 47, two; 49, one; 50, one); scales around body 35 to 46, average 42.2 (12 counts: 35, one; 38, one; 41, one; 42, one; 43, four; 44, three; 46, one). Femoral pores 11 to 14, average 12.5 (28 counts: 11, five; 12, eight; 13, eleven; 14, four). Habits and habitat. The specimens collected by Nelson and Goldman near Santo Domingo, Oaxaca, are said to have been found "in woods about tree butts and on logs and stumps." Locality records. VERA CRUZ: (ANSP 12435); Jalapa (MCZ 2853[6]; USNM 6308[4]); El Encero and Jalapa (USNM 2962). OAXACA: Mts. near Santo Domingo (USNM 47330-1). 1939 MEXICAN LIZARDS SMITH THE SPINOSUS GROUP 1 59 Twenty-one species and subspecies are included in the spinosus group. They are as follows: lunaei, acanthinus, melanorhinus, edwardtaylori, clarkii clarkii, clarkii boulengeri, orcutti orcutti, orcutti licki, lundelli lundetti, lundelli gaigeae, magister magister, magister H. ALBIVENTRIS S. SPINOSUS H. OLIGOPORUS KHORRIDUS. CAERULEOPUNCTATUS O. LICKI C. BOULENGERI C. CLARKII M. ZOSTEROMUS M MONSERRATENSIS MLINEATULUS M.RUFIDORSUM MELANORHINUS EDWARDTAYLORI L. GAIGEAE L. LUNDELLI FORMOSUS MALACHITICUS FIG. 7. Phylogeny of the spinosus group. rufidorsum, magister monserratensis, magister zosteromus, magister lineatulus, spinosus spinosus, spinosus caeruleopunctatus, olivaceus, horridus horridus, horridus oligoporus, and horridus albiventris. Two names have been synonymized: digueti Mocquard with orcutti orcutti, and guentheri Stejneger with acanthinus. S. floridanus, which has long been considered in this group (in fact, a subspecies of spinosus), has been placed in the undulatus group as a subspecies of undulatus, 1 Approximately 5,022 specimens examined. 60 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 following Burt (1936). Thereby olivaceus becomes available for the Texan and northern Mexican form previously referred to floridanus and is retained as a species. Other changes are few. S. magister is recognized as a species dis- tinct from clarkii; the Lower Californian forms, rufidorsum, monser- ratensis, zosteromus, and lineatulus, are considered to be subspecies of magister. S. m. monserratensis is regarded as inhabiting not only Monserrate Island but also southern Lower California, exclusive of the Cape region. S. licki, the Cape derivative of orcutti, is con- sidered a subspecies of the latter. S. horridus is revived as a species, including three subspecies. The most primitive form of the group is undoubtedly lunaei, which is closely related to formosus malachiticus. S. acanthinus is a near relative of lunaei, as is also lundelli. S. magister seems to be a derivative of the stock which gave rise directly to spinosus, while clarkii appears to be more closely related to mekmorhinus and lundelli. S. orcutti is rather definitely the western derivative of clarkii. The accompanying diagram illustrates my idea of the course of phylogeny in the group. The habits of the members of the group are highly variable. Some live almost entirely on the ground, others in rocks, others in trees. No species ascends to an elevation much greater than 5,500 feet. So far as known, all the species are oviparous. The characters held in common by members of this group are: absence of a dorsal, light-bordered nuchal collar; dorsal scales rela- tively large (minimum, 26; maximum, 40); dorsal scales strongly mucronate (except o. orcutti}; ventral scales smooth, notched; post- anals enlarged in males; scales on posterior surface of thigh large; supraoculars in a single series, usually very large, usually partially in contact with median head scales; femoral pores widely separated medially; dorsal surface not a brilliant blue in males (except lunaei and acanthinus); belly colored in males (except h. albiventris and edwardtaylori) ; relatively large size (maximum snout- vent measure- ment of smallest species, 86 mm. ; of largest species, 140 mm.). The following key to the species and subspecies of the group is submitted with reservations. The key is based on average scale counts; a certain small per cent of the specimens are expected to key out incorrectly. The group is so compact, with so many species and subspecies linking the poorly defined subgroups, that the key has of necessity been made artificial. Related species and subspecies are frequently widely separated in the key due to the use of some 1939 MEXICAN LIZARDS SMITH 61 character of minor importance, but easily defined. It must be emphasized that the key will not work backwards, as several times subgroups are selected out, one or two forms eliminated, and then the remainder of the species of the subgroup referred back to the body of the key. KEY TO THE SPECIES AND SUBSPECIES OF THE SPINOSUS GROUP 1. Femoral pores on both thighs total seven or more 3 Femoral pores on both thighs total six or less 2 2. Ventral surfaces immaculate in adults of both sexes. horridus albiventris (p. 108) Sides of belly blue, frequently dark-bordered, in males; gular region barred in males, sometimes in females horridus horridus (p. 98) 3. A dorsal nuchal collar present, about two scales wide, frequently abruptly broken medially by a narrow space one or two scales wide; outer row of labiomentals separated from mental; first canthal separated from lori- labials; belly patches in males passing across chest to gular region; femoral pores 12 or more; two series of dark spots down back in females. acanthinus (p. 74) No dorsal nuchal collar; or, if present, first canthal in contact with lori- labials and belly patches not extending over chest in males 4 4. Supraoculars completely in contact with superciliaries, or with one to four very small scales between; posterior superciliary greatly enlarged; venter immaculate in both sexes ' . . edwardtaylori (p. 78) Supraoculars separated from superciliaries by at least one row of small scales; posterior superciliary not enlarged; venter with distinct markings in males 5 5. Femoral pores on both thighs total 12 or less; four supraoculars, the fourth in contact with median head scales horridus horridus (p. 98) Femoral pores on both thighs total 13 or more; or, if 12, all supraoculars separated from median head scales 6 6. Femoral pores (one side) 17 or more 7 Femoral pores (one side) 16 or less 10 7. One canthal lunaei (p. 63) Two canthals 8 8. A black shoulder patch present, with a light posterior border 10 No black shoulder patch; or, if present, without a light posterior border. . .9 9. Snout black; a broad, black bar across head at middle of supraocular region; chest and middle of belly orange in males; gular region in females white, with irregular, black marks; first canthal not in contact with lorilabials; ventral scales 44 to 54 melanorhinus (p. 82) Snout not black, similar in color to rest of head; no black bar across head; chest and middle of belly not orange; gular region in both sexes bluish, with light lines following the scale rows at anterior part of throat; first canthal in contact with lorilabials; ventral scales 38 to 42. magister lineatulus (p. 168) 10. One or more supraoculars in contact with median head scales 15 None of supraoculars in contact with median head scales 11 11. Gular region barred 12 Gular region not barred 13 12. Dorsal scales usually more than 30; femoral pores usually more than nine (one side); supraoculars usually five to seven. spinosus caeruleopunctatus (p. 94) Dorsal scales usually 30 or less; femoral pores usually nine or less (one side); supraoculars usually four spinosus spinosus (p. 87) 62 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 13. One canthal lunaei (p. 63) Two canthals 14 14. Belly patches in males continuous across chest; pref rentals never in contact; no dorsolateral light lines in males; posterior surface of thigh mottled or with a broad light line, dark-bordered 15 Belly patches small, confined to sides of belly in males; prefrontals usually in contact; dorsolateral light lines present in males; posterior surface of thigh nearly immaculate or with a narrow, short black line near insertion of hind leg olivaceus (p. 110) 15. Gular region barred 16 Gular region not barred 17 16. Femoral pores 13 or more (one side) orcutti licki (p. 140) Femoral pores 12 or less (one side) spinosus spinosus (p. 87) 17. One canthal lunaei (p. 63) Two canthals 18 18. Femoral pores (one side) 12 or less 19 Femoral pores (one side) 13 or more 23 19. Outer row of labiomental scales in contact with mental. magister magister (p. 145) Outer row of labiomental scales separated from mental 20 20. First canthal in contact with lorilabials orcutti orcutti (p. 133) First canthal separated from lorilabials 21 21. Lateral scales about one-half size of dorsal scales; median frontonasal not in contact with frontal; lateral belly patches in males not passing over chest 23 Lateral scales considerably more than one-half size of dorsal scales; median frontonasal usually in contact with frontal; lateral belly patches in males passing over chest 22 22. Dorsal markings absent or very dimly visible; a broad, light line on posterior surface of thighs lundelli gaigeae (p. 71) Dorsal markings present and distinct at least in females, consisting of narrow, dark crossbars; posterior surface of thigh mottled, .lundelli lundelli (p. 66) 23. Femoral pores (one side) 10 or less 24 Femoral pores (one side) 11 or more 25 24. First canthal rarely in contact with lorilabials; gular region never barred; outer row of labiomentals rarely in contact with mental. clarkii boulengeri (p. 128) First canthal usually in contact with lorilabials; gular region barred, or outer row of labiomentals sometimes in contact with mental (not in o. orcutti) 25 25. First canthal separated from labiomentals; femoral pores 16 or less; lower forelegs distinctly barred; gular region never barred . clarkii clarkii (p. 118) First canthal in contact with lorilabials; lower forelegs not barred dis- tinctly 26 26. Outer row of labiomentals in contact with mental; gular region not barred; shoulder patch distinct 28 Outer row of labiomental scales separated from mental; gular region barred or shoulder patch indistinct 27 27. Dorsal scales 32 to 40; femoral pores 13 to 19; usually one or more scales in contact with both subocular and supralabials; a distinct, light-bordered, black shoulder patch; dorsolateral light lines present, indistinct posteriorly, the medial edge sometimes indistinct orcutti licki (p. 140) Dorsal scales 28 to 36; femoral pores 10 to 15; usually two complete rows of lorilabials below subocular; shoulder patch indistinct; no dorsolateral light lines orcutti orcutti (p. 133) 1939 MEXICAN LIZARDS SMITH 63 28. Supraoculars usually five; femoral pores (one side) usually 15 or less. magister magisler (p. 145) Supraoculars usually six or seven; femoral pores usually 16 or more 29 29. No dark lines in adult males on sides of lateral scale rows; femoral pores (one side) usually less than 19; lateral belly patches confluent medially in adult males magister rufidorsum (p. 161) Dark lines on sides of lateral scale rows present in adult males; lateral belly patches not confluent medially in adult males 30 30. A distinct, narrow dorsal stripe about one and two half scale rows wide; females and young with two rows of dark spots, one on either side of mid-dorsal stripe magister monserratensis (p. 165) A broad, light-colored dorsal area about six scale rows wide; dark spots on back absent or indistinct magister zosteromus (p. 170) Sceloporus lunaei Bocourt. Sceloporus lunaei Bocourt, Ann. Sci. Nat., Zool., (5), 17, No. 10, p. 1, 1873; idem, Miss. Sci. Mex., Zool., 3, sec. 1, pp. 184-186, pi. 18bis, figs. 5, 5a, 56, 1874; Cope, Proc. Amer. Phil. Soc., 22, p. 400, 1885; idem, Bull. U. S. Nat. Mus., 32, p. 37, 1887; Giinther, Biol. Cent.-Amer., Kept. Batr., p. 67, 1890; Cope, Ann. Kept. U. S. Nat. Mus., 1898, p. 335, 1900; Wettstein, Sitzber. Akad. Wiss. Wien, Math.-Nat. KL, 143, Abt. 1, p. 25, 1934; Smith, Proc. Biol. Soc. Wash., 49, p. 95, 1936. Sceloporus acanthinus Miiller, Verh. Naturf. Ges. Basel, 6, pp. 573, 633, 1878. Sceloporus formosus Werner, Abh. Bayer. Akad. Wiss., Math.-Phys. Kl., 22, Abt. 2, p. 344, 1903. Type locality. Plateau of Guatemala. Distribution. Known only from the Motagua Valley and the desert areas of Baja Verapaz, Guatemala (fig. 8). Diagnosis. A moderately large Sceloporus, maximum snout-vent measurement 95 mm. ; one canthal (the first entirely absent) ; supra- oculars moderate in size; sometimes one or two very small scales segmented off from outer parts of supraoculars; one complete and one or two incomplete series of scales between supraoculars and super- ciliaries; one or two posterior supraoculars frequently in contact with median head scales; frontal ridges distinct; dorsal scales 31 to 38; a black shoulder patch in males, none in females; females with two series of dark spots down back; males uniform greenish olive above. Description. 1 Head scales smooth, slightly convex, somewhat pitted; a weak depression at anterior edge of frontal; interparietal pentagonal, the sides parallel, about twice the size of either parietal; frontoparietals rectangular, one on each side, separated medially by contact of interparietal and frontal; frontal divided, the ante- rior section as broad as long, narrower posteriorly; four or five supraoculars, separated from median head scales by one row of small 1 Based on USNM 25219, from Guatemala. 64 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 scales and from superciliaries by one complete and another two- thirds complete row of small scales; superciliaries six, five visible from above; prefrontals very small, widely separated by contact of frontal and median frontonasal; lateral frontonasals about three- fifths the size of median frontonasal; posterior pair of internasals distinct, the other irregular; four postrostrals; subnasal present; one large canthal; loreal single, small; preocular entire; two postoculars; two rows of lorilabial scales, complete below subocular; four and one-half supralabials and five infralabials to a point below middle of eye. Mental triangular, with a labial border two-thirds that of rostral; four pairs of postmentals, the scales of the anterior pair in contact medially; outer row of labiomentals narrowly separated from mental by partial contact of first infralabial and first postmental; gular scales considerably larger posteriorly than anteriorly, notched; scales in gular fold region with two apical notches. Four auricular lobules, subequal in size, smaller than preceding scales, extending about one-third distance across ear opening; temporal scales keeled, mucronate, weakly denticulate, much smaller anteriorly than posteriorly, the largest subequal in size to largest scales between ear and nuchal pocket; scales below ear keeled, .mucronate; scales between nuchal pocket and arm somewhat larger than scales between ear and nuchal pocket, very weakly keeled, rather strongly mucronate, weakly denticulate. Dorsal scales weakly keeled, strongly mucronate, weakly dentic- ulate, in nearly parallel rows; lateral scales similar to dorsals, more strongly denticulate, somewhat smaller; ventral scales smooth, notched, about one-half size of dorsal scales; interfemoral scales slightly smaller than preanal scales. Dorsal scales of foreleg weakly keeled, mucronate, denticulate, those on upper foreleg slightly larger than dorsals on lower foreleg and about two-thirds to three-fourths size of dorsals on body; scales on posteroventral surface of lower foreleg keeled, mucronate, dentic- ulate; scales on anterior surface of same member smooth, somewhat larger than dorsal scales of lower foreleg; ventral scales of upper foreleg smooth, notched, about one-half size of ventral scales of lower foreleg; lamellar formula for fingers 10-14-17-17-12 (9-14-17-18-14). Dorsal scales of hind leg strongly keeled toward apex, very strongly mucronate, not denticulate, subequal in size, about three- fourths size of dorsals on body; scales on ventral and anterior sur- faces of thigh smooth; ventral thigh scales notched; scales on posterior 1939 MEXICAN LIZARDS SMITH 65 surface of thigh keeled, notched, subequal in size or slightly smaller than preanal scales; scales on ventral surface of shank smooth, notched, somewhat larger than dorsal scales of same member; lamellar formula for toes 8-12-18-20-14 (8-12-18-21-14). Dorsal caudal scales keeled, mucronate, not denticulate, some- what larger than largest dorsals on body; basal subcaudals smooth, somewhat irregular-edged; distal caudals becoming keeled, mucro- nate; enlarged postanals present; no postfemoral dermal pocket. Color. Males are uniform greenish olive above; toes indistinctly barred; tail not visibly barred; a black shoulder spot, extending across gular fold region, not extending onto shoulder; lower labial region greenish; anterior part of throat pinkish, posterior part dark blue; chest with a bluish tinge; sides of belly pale lavender, bordered medially by dark blue; the blue borders uniting on posterior part of chest, diverging slightly posteriorly and extending to, but not into, groin; preanal region bluish; ventral surfaces of limbs and tail dusky white. In other males the sides of the belly and chest are dark blue. In females, the ground color is darker than in males; a series of about ten very irregular dark brown spots on each side of back, the spots round posteriorly, narrow and somewhat serrate ante- riorly; about seven very irregular dark brown bars on sides; some- times a narrow, dark brown bar extending from anterior margin of arm insertion onto sides of neck; limbs with very narrow broken bands; digits barred. Ventral surfaces immaculate, with faint dark spots in gular region. A young specimen (26.6 mm. snout-vent) from Quirigua, Guate- mala (USNM 58526) has the throat and chest finely mottled; two rows of spots down each side of mid-dorsal line; a small, dark spot directly above anterior margin of arm insertion; digits very distinctly barred. Variation. The variation in cephalic scutellation of 14 specimens is as follows: two parietals on both sides in two; frontoparietal divided on one side in one; frontal touches interparietal in 11, separated by contact of frontoparietals in three; five superciliaries on both sides in two; supraoculars four to six (4, seventeen; 5, ten; 6, one); one or more supraoculars in contact with median head scales in eight; l prefrontals in contact medially in three, separated by contact of i frontal and median frontonasal in 11; frontonasals normal in all; subnasal present and one canthal in all; preocular divided on one side in one, on both sides in five; loreals one to three (1, nineteen; 2, eight; 3, one); lorilabials reduced to one row below subocular by 66 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 contact of one or more scales with both subocular and supralabials on one side in two, on both sides in five. Dorsal scales 31 to 38, average 34.7 (14 counts: 31, one; 33, two; 34, five; 35, one; 36, two; 37, two; 38, one); ventral scales 38 to 44, average 40.6 (14 counts: 38, one; 39, one; 40, one; 41, two; 42, four; 43, four; 44, one); scales around body 32 to 38, average 35.6 (14 counts: 32, one; 34, two; 35, four; 36, four; 38, three); femoral pores 12 to 17, average 14.9 (28 counts: 12, one; 13, three; 14, seven; 15, six; 16, eight; 17, three). Remarks. Sceloporus lunaei, as here considered, appears to be specifically distinct from /. malachiticus, f. smaragdinus, and acan- thinus. The differences from I. lundelli, which occurs in northern Guatemala and adjacent territories, are more obvious (see discussion under lundelli lundelli). S. lunaei differs from acanthinus by lacking the complete, broad nuchal collar, in having smaller supraoculars, larger scales, and in its single canthal. From /. malachiticus, lunaei differs in always having the supra- oculars entire; no light stripe down each dorsal scale row; and a somewhat different ventral coloration, the blue being practically uniform over the posterior part of throat, chest, and entire ventral surface of abdomen. A close relationship with /. malachiticus is shown in the females, which cannot be distinguished by color. The only difference observable in females lies in the supraoculars, which are entire in lunaei, divided in /. malachiticus. This difference is not con- stant, as some specimens of /. malachiticus have entire supraoculars. This species has been the most difficult in the group to define and place satisfactorily, due to lack of sufficient material with adequate data. It is not impossible that lunaei is a subspecies of formosus, intergrading with /. malachiticus, in which case it would become a member of the formosus group. I think it less likely that it intergrades with acanthinus, as the latter has numerous stable characters which differ from those of lunaei. Locality records. GUATEMALA: (ANSP 8481-4, 8486; MCZ 5832; USNM 6771[4], 25219-20); Quirigua (USNM 58526); Salama (FMNH 20674-5). Sceloporus lundelli lundelli sp. and subsp. nov. Sceloporus torquatus serrifer Stuart, Occ. Papers Mus. Zool. Univ. Mich., 292, p. 11, 1934. Type from Cohune Ridge (20 miles southeast of Benque Viejo), British Honduras. Museum of Zoology, University of Michigan No. 80674. Collected by C. L. Lundell. 1939 MEXICAN LIZARDS SMITH 67 Distribution. The base of the Yucatan Peninsula, from Cam- peche to British Honduras (fig. 8). Diagnosis. A Sceloporus of moderately large size, maximum snout- vent measurement 86 mm.; dorsal scales 28 to 34; supraoculars large, usually four or five, rarely six, the posterior one or two usually at least partially in contact with median head scales; frontal usually in contact with median frontonasal; two canthals, normal in position; one loreal; femoral pores nine to twelve. A black shoulder spot in males, sometimes connecting narrowly across dorsal surface of neck; FIG. 8. Distribution of the primitive forms of the spinosus group: Scelo- porus acanthinus, V; S. lunaei, O; S. lundelli lundelli, A; S. 1. gaigeae, ; S. edwardtaylori, D- females with narrow, undulate, dark gray bands across back; lateral blue patches on belly in males continuous across chest; middle of belly and chest dark blue; posterior surface of thigh mottled. Description of type. Head scales smooth, slightly convex, pitted; parietals single on either side; interparietal pentagonal, about two and one-half times as large as either parietal; frontoparietals single, in contact medially; five supraoculars, the anterior very small; fourth and fifth supraoculars broadly in contact with median head scales; one complete row of small scales between supraoculars and superciliaries; six superciliaries, five visible from above; median frontonasal in contact with frontal; two pairs of internasals; rostral 68 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 and internasals separated from rostral by four postrostrals; subnasal present, large; two canthals, normal in relationships with other scales, not touching lorilabials or forced above canthal ridge; preocular entire; lorilabials in two rows, reduced to one below sub ocular by contact of two scales with both subocular and supralabials; two postrostrals; four and one-half supralabials and infralabials to a point below middle of eye. Mental pentagonal, with a labial border slightly less than two- thirds that of rostral; outer row of labiomentals narrowly separated from mental by partial contact of first postmental and first infralabial; four pairs of postmentals, the scales of the anterior pair in contact medially; gular scales notched, those toward posterolateral region with two apical notches; scales below ear keeled, rather strongly mucronate. Auricular lobules three, subequal in size, their length somewhat greater than one-half the width of tympanum; auricular lobules slightly smaller than or subequal to preceding scales; temporal scales weakly keeled, mucronate, smaller than scales between ear and lateral nuchal pocket; latter scales weakly keeled, strongly mucronate, the mucrones recurving upward; these scales increasing in size dorsally, merging with dorsal body scales, greatly decreasing in size ventrally; scales immediately below and behind lower part of ear strongly keeled, strongly mucronate; scales between arm and lateral nuchal pocket subequal in size to scales anterior to nuchal pocket, weakly keeled, very strongly mucronate dorsally, weakly denticulate. Dorsal scales weakly keeled (only toward apex), very strongly mucronate, very weakly denticulate, in slightly convergent rows; 32 dorsals from occiput to base of tail; scales around body 31; ventral scales 42; lateral scales more strongly keeled, mucronate and denticulate than dorsal scales, about two-thirds size of dorsal scales, in oblique rows; all ventral body scales, including preanals, with a single apical notch; median ventral scales about one-fourth size of dorsal scales. Dorsal scales of foreleg keeled, mucronate, denticulate, about one-half size of dorsal scales on body; scales on anterior and antero- ventral surfaces of lower foreleg smooth, notched; other ventral scales of lower foreleg weakly keeled, mucronate; scales on ventral surface of upper foreleg smooth, with two apical notches, the scales increasing in size distally, the largest about two-thirds size of ventral scales of lower foreleg; lamellar formula for fingers 8-12-15-16-11 (8-12-16-17-11). 1939 MEXICAN LIZARDS SMITH 69 Dorsal scales of hind leg keeled, mucronate, not denticulate, somewhat larger than scales on foreleg; scales on anterior and ventral surface of thigh smooth, notched, smaller on ventral surface; femoral pores 10-11; scales on posterior surface of thigh keeled, denticulate, gradually increasing in size dorsally, the largest slightly smaller than preanal scales; ventral scales of shank smooth, denticulate, subequal in size to dorsal scales of same member; lamellar formula for toes 7-11-16-19-14 (6-11-15-19-15). Dorsal caudal scales similar to dorsal scales on body; subcaudals smooth and denticulate at base of tail; no postfemoral dermal pocket; postanals enlarged in males. Color. In males the dorsal ground color more or less uniform olive-gray; a black spot, not light-bordered, in front of insertion of foreleg; two shoulder spots sometimes connected across dorsal surface of body by a poorly outlined gray band; very faint irregular darker markings on sides of body; toes faintly barred; a light spot in middle of interparietal, and sometimes one in the middle of each parietal. Anterior part of gular region pale orange in large males, dusky white in smaller males; central and posterior part of throat iridescent greenish blue to darker cyanine blue, the edges or sometimes only the sides of the scales black or dark gray; shoulder patches some- times (in large males) confluent across ventral surface; the scales in this region, if not entirely black, dark blue with black edges; a broad median area on chest and down abdomen dark blue, the chest scales black-edged; median blue area on abdomen becoming black in exact middle of belly; sides of belly lavender, the color extending onto sides of chest; groin colored like sides of body; ven- tral surfaces of limbs and tail cream-colored. In females the dorsal ground color lighter than in males; no distinct black shoulder spot; a more or less distinct narrow neck band; about four narrow undulate dark gray bands across back, sometimes extending onto sides of body; a narrow irregular dark gray band extending posteriorly from near upper edge of lateral nuchal pocket to a point about one-third the distance between axilla and groin, where the band forks; both forks continuing poste- riorly, paralleling each other, to groin; tail with indistinct dark gray bars; limbs with narrow dark bars. Throat dirty white, with scattered light-colored scales; a faint barring sometimes evident on throat; abdomen and ventral surfaces of limbs and tail dusky white, lighter than throat. 70 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 In both sexes, the posterior surface of the thigh is mottled, the white areas of larger size than the dark. Variation. The variation in cephalic scutellation of 18 speci- mens is as follows: two parietals on one side in one; frontoparietals single in all; frontal touches interparietal in eight, separated by an azygous scale in one, by contact of frontoparietals in eight; frontal entire in one, normal in others; five superciliaries in nine, six in eight; supraoculars four to six (4, six; 5, twenty-six; 6, two); frontal and median frontonasal in contact medially in 16, separated by an azygous scale in one; frontonasals normal in all; subnasal present in all; two canthals in all, the first in contact with lorilabials in one, never forced above canthal ridge; preocular divided on one side in one, on both sides in one; three postrostrals in one, four in others; lorilabials reduced to one row below subocular by one or more scales in contact with both subocular and supralabials on both sides in two. Dorsal scales 28 to 34, average 31.9 (17 counts: 28, one; 29, one; 31, four; 32, six; 33, one; 34, four); ventral scales 38 to 45, average 40.6 (16 counts: 38, two; 39, three; 40, four; 41, three; 42, one; 44, two; 45, one); scales around body 30 to 36, average 33.3 (17 counts: 30, two; 31, one; 32, two; 33, three; 34, five; 35, two; 36, two). Femoral pores 9 to 12, average 10.6 (34 counts: 9, two; 10, fourteen; 11, fourteen; 12, four). Comparisons. S. lundelli lundelli is a form quite distinct, whose only close relative is I. gaigeae. It has a peculiar dorsal color pattern; the only species of the spinosus group with a similar pattern are clarkii clarkii and females of stejnegeri. From lunaei, lundelli lundelli differs by having two canthals (one in lunaei}; femoral pores usually fewer (12 to 17 in lunaei); dorsal scales average fewer (31 to 38, average 34.7, in lunaei); supraoculars larger, more regular; and color pattern different (two rows of spots down back in females of lunaei). Habits and habitat. The specimens collected at Balchacaj were all found on trees. Their gray coloration blends perfectly with the color of the trees on which they live. They are very cautious, moving very stealthily and quietly. They occur in the deepest parts of heavily wooded areas, as well as at the edges of woods, and may be seen on the few portions of the tree trunks or heavier limbs which are in the sun. Returning from a long tramp through the woods, I stopped for a rest underneath a relatively large tree at the edge of the woods, before starting the walk across the hot, open 1939 MEXICAN LIZARDS SMITH 71 savanna to the hacienda houses. After standing against the trunk a few moments, a snake's head protruding from a hollow limb caught my eye. I shot the snake, and at the same time disturbed a lundelli which was near the snake. After about ten minutes of close inspec- tion of the tree, two other specimens were discovered and shot. For secretiveness they are paralleled in my experience only by m. disparilis. A few s. serrifer were taken in the region about Bal- chacaj, but appeared to be much more easily discovered, occurring only low on the trunks of the trees. Their more brilliant coloration makes them more conspicuous than I. lundelli. Locality records. CAMPECHE: Jaina (USNM 46862); Balchacaj (EHT 9945-55). GUATEMALA: Uaxactun (MCZ 38665; UMMZ 70420-2). BRITISH HONDURAS: Belize River at El Cayo (UMMZ 80675); Cohune Ridge (UMMZ 80674). Sceloporus lundelli gaigeae subsp. nov. Sceloporus malachiticus Cope, Proc. Amer. Phil. Soc., 22, p. 397, 1885 (part); idem, Bull. U. S. Nat. Mus., 32, p. 36, 1887 (part). Sceloporus smaragdinus Gtinther, Biol. Cent.-Amer., Kept. Batr., pp. 88-89, 1890 (part). Sceloporus serrifer Barbour and Cole, Bull. Mus. Comp. Zool., 50, No. 5, p. 150, 1906. Sceloporus acanthinus Gaige, Carnegie Inst. Wash. Publ., 457, p. 297, 1936. Type from MeYida, Yucatan. No. 31524 Field Museum of Natural History. Female. Collected by H. M. Smith. Paratypes five, including two topotypes (E. H. Taylor Coll. 9942-3), and three from Chichen Itza, Yucatan (FMNH 27332^). Distribution. Northern part of the Yucatan Peninsula (fig. 8). Diagnosis. A Sceloporus of moderately large size, maximum snout- vent measurement 100 mm.; similar to S. lundelli lundelli in scutellation; no dorsal marks, or markings barely visible; shoulder spot not distinct; an indistinct narrow dorsal nuchal collar; a broad, light line on posterior surface of thighs. Description of type. Dorsal head scales smooth, pitted, not convex; a slight concavity in prefrontal and frontoparietal area; interparietal pentagonal; parietals single on either side, about one- half size of interparietal; frontoparietals more or less rectangular, single on each side, in contact medially; frontal typically divided; five large supraoculars on each side, the three posterior on each side completely in contact with median head scales; a short row of small 72 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 scales separating two anterior supraoculars from median head scales, and another row, nearly complete, separating supraoculars from all superciliaries except the first; six superciliaries, four visible from above; pref rentals separated by contact of frontal and median frontonasal; internasals irregular; four postrostrals; subnasal present, subequal in size to first canthal; two canthals, typical; preocular entire; loreal single; two strongly keeled postoculars; two irregular rows of lorilabials, reduced to one row below subocular by two scales in contact with both subocular and supralabial; four supra- labials and five infralabials to a point below middle of eye. Mental small, pentagonal, with a labial border slightly more than half that of rostral; three or four pairs of postmentals, the scales of only the anterior pair in contact medially; anterior scale of outer row of labiomentals separated from mental by partial contact of first infralabial and first postmental on each side; gular scales smooth, except those immediately below and behind ear, notched. Four auricular lobules, the three upper subequal in size, not extending across ear opening, smaller than preceding scales; temporal scales weakly keeled, weakly mucronate, increasing in size posteri- orly, the largest subequal in size to scales between ear and nuchal pocket; latter scales weakly keeled, strongly mucronate; a series of scales between nuchal fold and lower edge of ear, the scales strongly keeled, and mucronate; scales between nuchal pocket and arm weakly keeled, strongly mucronate, the largest somewhat larger than largest scales between ear and nuchal pocket. Dorsal scales smooth at base, keeled apically, strongly mucronate, denticulate, in slightly convergent rows; lateral scales more strongly keeled, mucronate and denticulate than dorsal scales, about two- thirds or three-fourths size of dorsal scales; ventral scales smooth, each with a single apical notch, the median scales slightly smaller than lateral scales or scales on chest; preanal scales subequal in size to, and interfemoral scales slightly smaller than, median ventral scales; dorsal scales 29 from occiput to base of tail; scales around middle of body 32; ventral scales 40. Dorsal scales of foreleg keeled, strongly mucronate, those on upper foreleg about one-half larger than those on lower foreleg, and about two-fifths size of dorsals on body; anterior ventral scales near hand keeled and mucronate; largest ventral scales of lower foreleg somewhat smaller than largest dorsal scales of same member; ventral scales of upper foreleg smooth or weakly keeled, weakly 1939 MEXICAN LIZARDS SMITH 73 denticulate, about one- third size of ventral scales on lower foreleg; lamellar formula for fingers 9-12-15-16-11 (8-11-13-15-11). Dorsal scales of hind leg keeled, mucronate, not or weakly denticu- late, those on shank somewhat larger than those on thigh, and about one-half size of dorsal body scales; scales on ventral surface of thigh smooth, some notched, some pointed, gradually increasing in size toward anterior surface of thigh; scales on posterior surface of thigh keeled, mucronate, not denticulate, subequal in size to interfemoral scales, slightly smaller than preanal scales; ventral scales on shank smooth, very weakly notched, subequal in size to dorsal scales of same member; lamellar formula for toes 6-10-16-19-13 (7-12-15- 19-14). Largest dorsal caudal scales somewhat smaller than largest dorsal body scales, similar in character; basal subcaudals smooth, pointed, the distal caudals becoming keeled, mucronate; no postfemoral dermal pocket; postanals enlarged in males. Color (in alcohol). Dorsal surface light olive-gray; head some- what lighter than body; an oval light-colored pineal spot, its lateral edges defined by a narrow black line; two faint parallel narrow bluish lines passing from anterior temporal region posteriorly above ear to shoulder; no large shoulder spot; an indefinite dark bluish- black nuchal collar, broken medially by a narrow area about the width of one scale; limbs with very narrow cross bands; back prac- tically uniform, with very faint evidence of crossbarring similar to the pattern in I. lundelli; two indefinite narrow and broken dark lines on sides of body, united above and behind axilla, extending forward from this point as a single line on each side to nuchal collar; tail faintly barred; ventral surfaces immaculate creamy white; infralabial region somewhat dusky. A male of moderate size (85 mm. snout to vent) shows no evidence whatsoever of marks on the back; fingers and toes barred; tail not barred; nuchal collar narrow, complete, much broader in front of arm insertion; gular region and posterior part of throat dark blue, the scales in the gular fold region black-edged; anterior part of chest campanula blue; middle of chest and a narrow streak down middle of abdomen white; area adjacent to median white streak black, bor- dered laterally by a narrow iridescent greenish blue area, this bordered laterally by a broader campanula blue area; anterior part of throat dusky white, faintly tinged with pink (possibly light orange in life); ventral surfaces of limbs and tail white. In two male paratypes of larger size, the light ventral abdominal streak is confined 74 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 to the middle and posterior part of the belly. In one of the adult males, the anterior part of the gular region is bright tomato red, with a few indistinct light gray convergent bars. A young female (62 mm. snout to vent) shows markings typical of I. lundetti; these markings are nearly or quite obsolete in all other specimens. In both sexes, a broad longitudinal light line usually passes across the posterior surface of the thigh; the band is bordered below by a narrow dark line becoming indistinct distally, and above by the gray dorsal ground color of the thigh. In some specimens there are no marks on the posterior surface of the thigh. Variation. The cephalic scutellation of the eleven specimens studied varies from that of the type as follows: two parietals on both sides in two; frontal touches interparietal in six, separated by contact of frontoparietals in five; five superciliaries on one side in one; four supraoculars on both sides in two, five in eight, six in one; three postrostrals in one, four in others; two complete rows of lorilabials below subocular on both sides in six. Comparisons. The present subspecies differs from I. lundetti only in coloration, as stated in the diagnosis. The subspecies has long been confused with s. serrifer, from which it is quite different. There is no broad, light-bordered nuchal collar in 1. gaigeae (always present in serrifer); some of the supraoculars are always in contact with the median head scales in I. gaigeae, usually not in serrifer; the frontal is in contact with the median frontonasal in 1. gaigeae (rarely in serrifer). The two species occur together at MeYida, although inhabiting different ecological niches. Only I. gaigeae, so far as I am aware, has been taken at Chichen Itzd. Habits and habitat. Like L lundetti, this subspecies seems to prefer trees. The specimens I collected at MeYida were found on large, light-barked trees. All the s. serrifer in this area were on stone fences and on buildings. Locality records. YUCATAN: (USNM 24875); Chichen Itza (MCZ 7119, 29236; UMMZ 72880); Mil, Cat. Mth., p. 77, 1851; Westphal-Castelnau, Congr. Scient. France, 35, p. 285, 1872. Sceloporus spinosus horridus Boulenger, Cat. Liz. Brit. Mus., 2, p. 227, 1885 (part); idem, Proc. Zool. Soc. Lond., 1897, pp. 491, 493-495, 1897 (part); Ahl, Zool. Anz., 106, p. 184, 1934. Sceloporus spinosus Giinther, Biol. Cent.-Amer., Kept. Batr., pp. 63-64, 1890 (part); Gadow, Proc. Zool. Soc. Lond., 2, p. 194, 1905 (part). Type locality. Mexico. Distribution. Southern Morelos, eastern Guerrero, Oaxaca in the Balsas Basin, southern Puebla (fig. 11). Diagnosis. A moderately large species, maximum snout-vent measurement about 113 mm.; cephalic scales smooth; dorsal scales 28 to 34 from occiput to base of tail, keeled, mucronate, denticu- late; supraoculars usually four in number (rarely five), the fourth almost always in partial contact with median scales; superciliaries FIG. 11. Distribution of Sceloporus horridus horridus, Q; S. h. oligoporus, V ', S. h. albiventris, A; and S. olivaceus, X. 100 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 separated from supraoculars by a single row of small scales; frontal usually contacting the interparietal; prefrontals in contact medi- ally in 30.6 per cent; preocular entire on one or on both sides in 82.4 per cent; lorilabials almost always in two complete rows below subocular; outer row of labiomentals rarely contacting mental; auricular lobules irregular, small; femoral pores on each side three to six, usually four or five, rarely six, totaling on both sides usually seven or more. Males with sides of belly blue, black, or dark blue bordered; gular region blue in males, black or dark blue barred; females with narrow, serrate, or undulate crossbars on back; gular region barred in females; no series of light spots on back. Description. 1 Head scales smooth, rather strongly convex; inter- parietal pentagonal, about twice the size of either parietal; parietals single on each side; frontoparietals square, separated from each other by contact of frontal and interparietal; frontal transversely divided, the posterior section about three-fifths the size of the anterior section; prefrontals in contact medially; three frontonasals, the median scale about the size of a prefrontal, slightly larger than either lateral frontonasal; latter scales in contact on each side with both canthals; median frontonasal preceded by two small, broad scales, these preceded in turn by a pair of internasals separated from the nasal on each side by one scale and from the rostral by two small scales; one small and three large supraoculars on each side, all except the fourth separated from median head scales; scales in the row be- tween supraoculars and median head scales decreasing in size posteriorly; two small scales inserted between parietal and last supraocular, leaving only about one-fourth of the medial edge of the latter scale in contact with the frontoparietal ; a single row of small scales between supraoculars and superciliaries; six superciliaries on each side, the last somewhat enlarged and protrudent; two canthals, normal; nasal single, nostril pierced nearer posterior edge than anterior; three small scales behind nasal; a small scale between anterior canthal and broad scales in front of median frontonasal; subnasal long, narrow; loreal single; preocular divided on one side, entire on other; subocular moderate in size, followed posteriorly by two keeled postoculars; two rows of lorilabials, not reduced to one row below subocular; one row of lorilabials, beginning below subnasal, continuous around snout; lorilabials on sides of head keeled; four supralabials and five infralabials to a point below middle of eye; labials not keeled, not imbricating. 1 Based on EHT 8560, male. 1939 MEXICAN LIZARDS SMITH 101 Rostral low, its upper edge slightly V-shaped; mental pentagonal, its labial border slightly more than half that of rostral; scales of outer row of lorilabials imbricating posteriorly, the anterior scale separated from mental by partial contact of first infralabial and first postmental; inner row of labiomentals terminating anteriorly about even with suture between second and third infralabials; three pairs of well-differentiated postmentals, the scales of the anterior pair in contact medially; gular scales smooth, approximately equal in size (except small scales between postmentals), the anterior scales slightly smaller than the others; all of gular scales except the anterior ones with one or two apical notches; some of scales immediately below ear keeled and mucronate; scales in gular fold region with no more than two terminal mucrones. Three or four well-differentiated, smooth, rounded or pointed auricular lobules, the largest subequal in size to or slightly smaller than preceding scales; temporal scales keeled, mucronate, five between postoculars and auricular lobules (minimum) ; scales between ear and lateral nuchal fold somewhat larger than temporal scales, keeled, strongly mucronate, denticulate. Dorsal scales keeled, strongly mucronate, denticulate, not reduced in size between hind legs; lateral scales somewhat smaller than dorsals, slightly more strongly keeled, mucronate and denticulate; scales in axilla very small (almost granular), but imbricating; scales in groin smooth, mucronate and notched, about one-third or one- fourth size of median lateral scales; ventral scales on chest and abdomen with one or two notches; scales on chest between axillae somewhat smaller than scales on anterior part of chest; abdominal scales becoming larger posteriorly and toward sides of abdomen; largest preanal scales slightly smaller than gular scales, a little more than one-half the size of scales on ventral surface between hind legs; some of preanal scales pore-like. Dorsal scales of foreleg keeled, mucronate, denticulate, those on upper foreleg about two-thirds size of dorsal scales on body, about one-third larger than scales on lower foreleg; scales on elbow reduced in size; ventral scales of foreleg smooth except toward hand, mucro- nate and notched, those on lower foreleg subequal in size to dorsal scales of same member, three or four times as large as ventral scales of upper foreleg; lamellar formula for fingers 7-12-17-17-10 (7-12- 16-17-11). Dorsal scales of hind leg keeled, mucronate, not or weakly den- ticulate, those on thigh slightly less than two-thirds size of largest 102 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 dorsal scales on body, equal to or slightly smaller than dorsal scales on shank; ventral scales on shank smooth, rounded or notched, sub- equal in size to dorsal scales of same member; scales on anterior surface of thigh equal in size to dorsal scales of same member, decreasing slightly in size on the ventral surface toward series of femoral pores, and becoming smooth, notched; scales in front of femoral pore series subequal in size to preanal scales; scales on posterior surface of thigh considerably smaller than preanals; scales at posterior margin of insertion of hind leg very small; no post- femoral dermal pocket; lamellar formula for toes 9-12-16-20-13 (8-11-16-19-13). Dorsal caudal scales strongly keeled, strongly mucronate, not denticulate, the largest no larger than dorsal scales on body; sub- caudals mucronate, notched toward base of tail, keeled except on the proximal fifth of the tail; enlarged postanals present, separated from each other by two small scales. Color. Adult males brownish-olive above; a dorsolateral light line on each side, originating on each side of neck and terminating on base of tail; inner (median) border of this light line very indis- tinct, fading into the general color of a broad area on middle of back; lateral border of dorsolateral light stripe usually distinct, with a dark band below it, extending from posterior corner of eye to shoulder (this part very narrow), thence to base of tail, this dark band occa- sionally indistinct or broken; sides of body with narrow transverse black bars; labia barred; limbs indistinctly banded; a dark longi- tudinal line on outer surface of shank; posterior surface of thigh with two longitudinal dark lines, the lower shorter, separated from each other by a white line; dark markings on back absent or very indis- tinct; a large black spot on shoulder, usually enclosing from one to three irregular small blue spots. Middle of gular region dark to pale blue, the color sometimes extending onto labia; labia usually somewhat tinged with orange, with a number of dark blue bars converging toward middle of throat, where they become more distinct; sides of belly cyanine blue, some- times darker medially, but usually not distinctly dark-bordered; the dark bars on sides of body frequently passing through belly patches; ventral surfaces of limbs, tail, chest, and a band down middle of abdomen cream or flesh color; no dark markings in these latter areas. Females similar to males, with the following exceptions: general ground color olive-gray; lateral dark band indistinct or broken; 1939 MEXICAN LIZARDS SMITH 103 undulate or serrate narrow dark bands across back; throat with blue-gray bars, not fusing medially; abdomen otherwise immaculate. Young much as in females, the dorsal transverse bars more distinct, eight or nine in number, sometimes with light spots scattered across their posterior borders; throat barred as in adults. In life the females are red-headed, and can easily be distinguished from males at a distance. Variation. The following data on variation in the scutellation of the head have been taken from 68 specimens. Parietals and fronto- parietals single on each side in all; frontoparietals in contact medially in one, separated by an azygous scale in three; frontal in contact with interparietal in 64; frontal entire in one; supraoculars three to five (136 counts: 3, two; 4, one hundred and thirty-one; 5, three); fifth supraocular in partial contact with median head scales in all but three (data recorded in 160), and on one side in one of these; prefrontals in contact medially in 26, separated by an azygous scale in 24; median frontonasal in contact with frontal in 35; first canthal touching lorilabials in four (fused abnormally with loreal in one of these); second canthal in contact with subnasal on both sides in one specimen, on one side in four; preocular divided on both sides in 15, on one side in 11 (85 specimens examined) ; lorilabials in two complete rows below subocular in all but one; outer row of labio- mentals in contact with mental on both sides in two specimens, on one side in one. Dorsal scales 28 to 34, average 30.5 (37 counts: 28, two; 29, five; 30, fourteen; 31, nine; 32, five; 33, one; 34, one); ventral scales 33 to 44, average 39.5 (37 counts: 33, two; 34, one; 35, three; 36, four; 37, four; 38, four; 39, six; 40, two; 41, six; 42, two; 44, three); scales around body 30 to 37, average 33.1 (37 counts: 30, one; 31, five; 32, eleven; 33, eight; 34, three; 35, four; 36, three; 37, two). Femoral pores two to six (2, three; 3, eighty- three; 4, one hundred and sixty; 5, sixty-four; 6, ten). Ninety- two other specimens from Chilpancingo were counted; one had the count of two-three; the remainder had counts from three to five (numbers not recorded). In total number of pores per specimen, the counts are as follows (150 counts: 4, one; 5, one; 6, twenty-seven; 7, seventeen; 8, fifty-nine; 9, nineteen; 10, nineteen; 11, four; 12, three). Remarks and relationships. I conclude that horridus and spi- nosus do not intergrade. The closest approach of their ranges is in Oaxaca (unless the locality records from the city of Puebla are correct, in which case it is certain that spinosus and horridus over- 104 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 lap), into which state horridus follows the Rio Balsas basin. Speci- mens of spinosus spinosus from localities in Oaxaca north of the Rio Balsas average the same as specimens well within the range of the subspecies; specimens from localities in Oaxaca south of the river have a much higher number of femoral pores than spinosus spinosus. No population of spinosus spinosus has been observed with a tendency stronger than average of the supraocular scales to parallel the condition in horridus. A single specimen having the characters of horridus horridus is stated to have been collected in the Valley of Mexico (MCZ 339911, collected by W. W. Brown). I believe the locality to be incorrect; specimens of other species collected by Brown also appear to bear erroneous locality data. Much collecting in the Valley of Mexico has not revealed other specimens of horridus. The distinctness of horridus horridus and h. oligoporus is less obvious. The greatest difference lies in the number of femoral pores. I have counted the pores on all specimens examined of both sub- species (although the data were recorded on less than half), and separation of the two on this character seems not a matter of prej- udice. There is admittedly a considerable overlapping (on the count of three), but a series of three or four from one locality is sufficient for correct allocation, although identification of a single specimen at hand may sometimes be difficult. Only two specimens of horridus horridus examined have two femoral pores on one side (three on the other), and one with two on both sides. The former two were collected near Chilpancingo, Guerrero, the latter specimen near Puente de Ixtla, Morelos. A sufficient number of specimens is available from both localities to demonstrate that these counts are aberrant. Four specimens from Xaltianguis, Guerrero (near the coast), have only the count of two; one specimen from Zihuatenejo, Guerrero, has the count of two-two; and three specimens from Balsas (city), Guerrero, have the count of two-two; these specimens have been placed with h. oligoporus. The present collections do not demonstrate how far southeast near the Pacific coast h. oligoporus extends; prob- ably, it extends no farther along the Balsas River than Balsas; specimens taken near Mexcala, about 30 km. up the river, show an average femoral pore count between that of typical horridus horridus and h. oligoporus; the counts are three-three (seven) and four-four (three). This is considered an intergrading population. In the following summary of femoral pore counts the two counts for each specimens are totaled: 1939 MEXICAN LIZARDS SMITH 105 h. horridits h. oligoporus 4-12 (160) 4-7 (114) Range Per cent Per cent Average 8.0 4.7 5 or less 1.3 75.4 6 or less 19.3 97.4 7 or less 30.7 100.0 Arbitrarily assuming the line of division between the two forms to be between six and seven, those falling below being h. oligoporus, and those above, h. horridus, 19.3 per cent of h. horridus would be incorrectly identified, and 2.6 per cent of h. oligoporus. Using the number of femoral pores as the key character, only 12.1 per cent of the total number of specimens of both subspecies would be incor- rectly allocated. Two other characters very nearly approach the femoral pore count in value for diagnosis of the two subspecies: h. horridus h. oligoporus Per cent Per cent Prefrontals in contact 30 . 6 73 . Preocular entire on one or both sides 82 .4 12 .2 Preocular divided on one or both sides 30.6 92.1 Habits and habitat. This subspecies is found on Opuntias and rock walls in relative abundance. Individuals observed seemed not extremely wary. Locality records. GUERRERO: 11-12 mi. S of Puente de Ixtla (EHT 8555, 8587-91, 8627-8, 8636, 8647-8); Taxco (EHT 8592-5); El Naranjo (EHT 8596-7); 16 km. N of Mexcala (EHT 8598); Mexcala (EHT 8559-60, 8599-8600, 8637-8, 8655-7, 8659); Chil- pancingo (EHT 8601-3, 8602A; UMMZ 72413[10]; MCZ 33851-78, 33880-33900 [+45]; USNM 47198,47733; WM 2; SDSNH 16304-5); 16 km. S of Chilpancingo (EHT 8586A); 12-14 mi. S of Chilpancingo (EHT 8604-9, 8609A, 8612, 8618-9, 8639-41, 8658); Tierra Colorada (EHT 8610-1, 8624, 8642; WM 4); between Cajones and Acahuizotla (EHT 8625); Palo Blanco (EHT 8643); 3 mi. N of Taxco (EHT 8660); Lake Tuxpan, near Iguala (EHT 8622-3); Acuitlapan (EHT 8654); Canada de Ixtapa (Sumichrast, 1882); Ayutla (Gadow, 1905); Chilapa (Ahl, 1934). MORELOS: 2 mi. N of Cuernavaca (EHT 8567-71, 8569A); Cuernavaca (EHT 8572-81; MCZ 33912; USNM 20177-8, 20173-6; LSJU 3785-92, 3798, 3803-8); 9 mi. S of Cuernavaca (EHT 8582-6); Puente de Ixtla (EHT 8613; FMNH 1012[4]; USNM 47928-30); Cuautla (EHT 8614; FMNH 1281[7]); 4 mi. S of Cuernavaca (EHT 6556-8, 8615-7, 8629-35, 8649-53); 5 mi. S of Puente de Ixtla (EHT 8644-5) ; Jojutla (FMNH 1290 [5]); Yautepec (FMNH 1352); Amitcingo (EHT 8626); Xochicalco (MCZ 9542). OAXACA: Chazumba (EHT 8620); Cuicatlan (EHT 106 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 8561-6; USNM 47195, 47613, 46838, 47458-9, 47367); Huajuapam (USNM 47193). PUEBLA: Zapotitlan (EHT8646); (?)Puebla (USNM 47699; AMNH 17990, 18795). Sceloporus horridus oligoporus Cope. Sceloporus oligoporus Cope, Proc. Acad. Nat. Sci. Phila., 1864, pp. 177-178, 1864; Sumichrast, Bibl. Univ. Rev. Suisse, 46, p. 243, 1873; Van Denburgh, Proc. Acad. Nat. Sci. Phila., 1897, p. 463, 1898; Stejneger, N. Amer. Fauna, 14, p. 67, 1899. Tropidolepis horridus Duges, Naturaleza, 1, p. 143, 1870. Sceloporus horridus Bocourt, Miss. Sci. Mex., Zool., 3, sec. 1, pp. 178-179, pi. 18, figs. 8, 8a, 86, 1874 (fig. of h. oligoporus) (part); Garman, Bull. Essex Inst., 16, p. 17, 1884 (part); Cope, Proc. Amer. Phil. Soc., 22, p. 396, 1885 (part); idem, Bull. U. S. Nat. Mus., 32, p. 35, 1887 (part); idem, Ann. Kept. U. S. Nat. Mus., 1898, pp. 353-354, 1900 (part). Sceloporus spinosus horridus Boulenger, Cat. Liz. Brit. Mus., 2, p. 227, 1885 (part); idem, Proc. Zool. Soc. Lond., 1897, pp. 491, 493-495, 1897 (part). Sceloporus spinosus Giinther, Biol. Cent.-Amer., Kept. Batr., pp. 63-64, 1890 (part); Gadow, Jorullo, pp. 55, 57, 1930 (part). Sceloporus boulengeri(l) Van Denburgh, Proc. Calif. Acad. Sci., (2), 6, p. 341, 1896; (?) idem, Proc. Acad. Nat. Sci. Phila., 1897, p. 463, 1898. Sceloporus clarkii boulengeri Burt, Trans. Amer. Micr. Soc., 54, pp. 171-172, 1935 (part). Sceloporus horridus oligoporus Taylor, Univ. Kans. Sci. Bull., 24, p. 520, 1938. Type locality. Colima, Colima, Mexico. Cotypes USNM 31386- 93, collected by John Xantus. Distribution. Western Guerrero, southern and central Michoa- can, Colima, and central Jalisco (fig. 11). Diagnosis. Most characters as in horridus horridus. Frontonasal rarely contacting frontal; prefrontals usually in contact; preocular usually divided; femoral pores two or three, rarely four, rarely totaling more than six on both sides. Color pattern essentially as in horridus horridus; lateral light lines more distinct; transverse bars on back indistinct, frequently replaced by more or less rounded light spots (especially in males), which form two series on each side of the mid-dorsal line; females without any markings whatsoever on ventral surfaces; males usually with fairly distinct convergent blue bars on throat; sides of belly in males with markings similar to those in horridus horridus, somewhat lighter. Variation. The following data on variation in head scutellation have been taken on 89 specimens. Frontoparietals in contact medially in nine, separated by an azygous scale in eight; frontal in contact with interparietal in 72; prefrontals in contact medially in 65, separated by an azygous scale in 17; median frontonasal in con- 1939 MEXICAN LIZARDS SMITH 107 tact with frontal in seven (abnormal fusion in one case) ; five supra- oculars on one side in three specimens, four in all others; first canthal in contact with lorilabials on one side in one, on both sides in one; second canthal in contact with subnasal on one side in one, on both sides in one; preocular divided on both sides in 90 speci- mens, on one side in three (101 examined) ; lorilabials reduced to one row by contact of a single scale with both suboculars and supra- labials on one side in one, on both sides in four; outer row of labio- labials in contact with mental on one side in four, on both sides in four. Other scale characters vary as in horridus horridus. Dorsal scales 27 to 33, average 30.8 (37 counts: 27, two; 28, one; 29, five; 30, eight; 31, seven; 32, seven; 33, seven); ventral scales 35 to 43, average 37.4 (36 counts: 35, five; 36, nine; 37, six; 38, four; 39, five; 40, three; 41, two; 42, one; 43, one) ; scales around body 29 to 36, average 32.8 (37 counts: 29, two; 30, one; 31, three; 32, eight; 33, twelve; 34, four; 35, six; 36, one). Femoral pores two to four, average 2.3 (230 counts: 2, one hundred and fifty-eight; 3, sixty-nine; 4, three) ; total number of femoral pores for each specimen four to seven, average 4.7 (114 specimens: 4, seventy; 5, sixteen; 6, twenty-five; 7, three). Habits and habitat. The subspecies seems to be fond of rock fences, where many were collected in Colima and Michoacan. At Uruapan, the few specimens encountered were on the ground, scurry- ing about in the oak leaves and pine needles. They usually took refuge under rocks; one sought a small tree, from which it was shot. Locality records. DuRANGO: Ventanas (Boulenger, 1885). ZACA- TECAS: San Juan Capistrano (USNM 46932-3); Valparaiso (USNM 47815). JALISCO: (USNM 46935); Hda. de Santa Maria, near Magdalena (AMNH 18455-6) ; Jamay to Hda. de Capulines (AMNH 18430); Guadalajara (AMNH 17978; USNM 24924); W of Hostoti- paquillo (AMNH 15516); Itzatlan (USNM 47886); Huejuquilla (USNM 46928); Atemajac (USNM 47892-3); Bolanos (USNM 46929); Chapala (USNM 18977; EHT 8488, 8526-8, 8510); Magda- lena (EHT 8521-5, 8468-74; AMNH 18465); La Quemada (EHT 8520); Ixtlan (Boulenger, 1897); Puentillo de Acatan (Boulenger, 1897); N of Rio Santiago (Gunther, 1890). MICHOACAN: Uruapan (EHT 8493-4, 8550); Hda. El Sabino (EHT 8495-8509, 8529-49); Jorullo (Gadow, 1930). COLIMA: (FMNH 1656) ; La Quinta (AMNH 15510); Colima (AMNH 15635-45, 15654, 15751-2, 12743, 12751, 12754, 12767-9, 15515, 12744; USNM 31386-93, 31497-501, 31466- 77, 63854); 4 mi. NE of Colima (AMNH 12739); 4 mi. SE of Colima 108 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 (AMNH 12740); 5 mi. SW of Colima (AMNH 12766); Villa Alvarez (UMMZ 80060[6], 80073, 80074[3], 80075, 80079[2]; AMNH 15511); San Cayetano (AMNH 15513); Estancia (AMNH 15514); Manza- nillo (EHT 8484-7); Hda. La Queseria (EHT 8475-83; UMMZ 80072[2]); Hda. Paso del Rio (UMMZ 80078[4], 80077[3]; EHT 8489- 92); Salvador (UMMZ 80076[3]). GUERRERO: Balsas (FMNH 1010 [2], 1726); Zihuatenejo (LMK 7335); Xaltianguis (EHT 8551-4). Sceloporus horridus albiventris subsp. nov. Type from Tepic, Nayarit, No. 8519 Taylor Collection. Male. Collected in 1934 by Edward H. Taylor. Paratypes (six topotypes), E. H. Taylor Coll. 8511B, 8511-2, 8514, 8517, 8519A. Distribution. Northern Jalisco to southern Sinaloa, in the coastal region (fig. 11). Diagnosis. A Sceloporus of moderately large size, maximum snout-vent measurement about 102 mm.; scutellation similar to that of horridus oligoporus; dorsal scales 29 to 33; supraoculars usually four, the fourth usually in partial contact with median head scales; frontal usually in contact with interparietal; preocular usually divided; femoral pores on each side two or three, rarely four, rarely totaling, on both sides, more than six. Dorsal color pattern similar to that in horridus oligoporus; a dorsolateral light line present; a row of small dark spots and a row of similar light spots (each about the size of a scale) on each side of mid-dorsal line; ventral surfaces in both sexes immacylate or, in males, with very slight tinges of blue on sides of abdomen, and very faint evidence of gular bars. Description of type. Head scales smooth, pitted; interparietal moderate in size, pentagonal; one parietal on each side, slightly more than half the size of interparietal; frontoparietals rectangular, narrowly separated medially by contact of frontal and interparietal; posterior section of frontal quite small, a little less than half the size of anterior section; two prefrontals, in contact medially; three frontonasals, the median the largest, the lateral scales separated from first superciliary; internasals irregular; nasal separated from rostral; four-four supraoculars, the anterior the smallest, the pos- terior the largest; first supraocular in contact with first and second superciliaries; a row of scales, beginning anteriorly at the first super- ciliary, intercalated between the first three supraoculars and the median head scales, terminating very slightly posterior to the suture between the third and fourth supraoculars; another row of small 1939 MEXICAN LIZARDS SMITH 109 scales intercalated between parietal and fourth supraocular, leaving the frontoparietal almost completely in contact with the fourth supraocular; five superciliaries visible from above on each side; a single row of small scales intercalated between the supraoculars and superciliaries, terminating anteriorly at the first supraocular; two canthals on each side, the second somewhat larger than the first and entering into the superciliary series; subnasal present, moderately large; three loreals on one side, two (the lower very small) on the other; preocular transversely divided on both sides, the lower part split into two scales on one side; subocular rather short, followed posteriorly by two small, keeled postoculars, two rows of lorilabials, not reduced to one row at any point below subocular; lorilabial scales weakly keeled on sides of head; approximately four supra- labials and five and one-half infralabials to a point below middle of eye; posterior labials weakly keeled. Mental pentagonal, its labial border slightly more than one-third that of rostral; two pairs of fairly well-developed postmentals, the scales of the anterior pair in contact medially, the scales of the pos- terior pair separated by several small scales; gular scales smooth, with one or two apical notches; median gular scales somewhat larger than lateral gular scales; scales immediately below ear weakly keeled. Temporal scales weakly keeled, weakly mucronate, somewhat larger than largest scales between ear and lateral nuchal fold ; auricu- lar lobules small, acuminate, smooth; scales posterior to ear quite small, becoming larger, more strongly keeled and strongly mucronate toward lateral nuchal fold; dorsal scales keeled, strongly mucro- nate, weakly denticulate (more strongly on neck), and reduced in size posterior to occiput; median lateral abdominal scales somewhat smaller than median dorsals, more strongly denticulate; ventral scales on body from chest to interfemoral region approximately equal in size, about two-thirds size of median dorsal scales, smooth, with one or two (usually two) apical notches; scales in interfemoral and preanal regions somewhat reduced in size; some of preanal scales pore-like; gular scales somewhat smaller than scales on belly. Dorsal scales of foreleg keeled, mucronate, those on upper foreleg about one-half size of largest dorsal scales on body, somewhat larger than dorsal scales on lower foreleg; ventral scales of lower foreleg smooth anteriorly, keeled posteriorly and toward hand, considerably larger than ventral scales of upper foreleg; latter scales very weakly keeled; lamellar formula for fingers 8-13-16-17-11 (8-12-17-16-11). 110 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 Dorsal scales of thigh and shank mucronate, denticulate, strongly keeled, subequal in size, somewhat larger than dorsal scales of upper foreleg; ventral scales of shank smooth, rounded or acuminate; scales on anterior surface of thigh somewhat smaller than dorsal scales of same member, the scales becoming smaller, smooth and acuminate ventrally toward femoral pore series; largest scales on posterior sur- face of thigh somewhat smaller than preanal scales, keeled, mucro- nate, denticulate; scales on posterior surface of thigh largest medially, becoming smaller distally and proximally; no postfemoral dermal pocket; postanal scales enlarged, separated from each other medially by two small scales; lamellar formula for toes 8-13-17-22-13 (8-12- 16-19-13). Scales on rump very slightly reduced in size; dorsal caudal scales not larger than dorsals on body, keeled, strongly mucronate, not denticulate; subcaudals smooth proximally, acuminate. Color, Much as in horridus oligoporus, except belly immaculate in both sexes or, in males, a slight suffusion of pale blue on sides of abdomen, and faint indications (in some) of gular bars. Remarks. I have been unable to discern any consistent differ- ences in scutellation between horridus oligoporus and horridus albi- ventris. The essential difference lies in the ventral coloration of the males. In horridus oligoporus, the adult males have distinct bars on the gular region, and the lateral belly marks are quite distinct; the ventral maculation is not so brilliant as in horridus horridus, however. In horridus albiventris there is no evidence whatsoever, in adult males, of the typical ventral maculation, except a very slight bluish tinge on the sides of the abdomen and (in some) faint gular bars. Locality records. SINALOA: Rosario (USNM 47677-8, 47681). NAYARIT: Mt. San Juan, near Tepic (EHT 8511A, 8519A); Tepic (USNM 58812-3, 64669); Telatan (AMNH 15518); between Bar- ranca Blanca and Trepichillo (AMNH 15520). JALISCO: San Sebas- tian (USNM 64656). . Sceloporus olivaceus Smith. Sceloporus spinosus Hallowell, in Sitgreaves, Kept. Exped. Zuni Colorado R., p. 144, 1854; Baird, in Emory, U. S.-Mex. Bound. Surv., 2, pt. 2, No. [3], p. 5, 1859 (part=figs. of magister magister); idem, U. S. Pacif. R. R. Explor. Surv., 10, Lieut. Whipple's Rept., p. 37, 1859; Cope, Bull. U. S. Nat. Mus., 1, p. 49, 1875; idem, 17, pp. 17, 44, 46, 1880; Hurter, Cat. Rept. Batr., Missouri, 1883; Yarrow, Bull. U. S. Nat. Mus., 24, p. 63, 1883 (part); idem, Smithson. Misc. Collec., 517, p. 10, 1883 (part); Cragin, Bull. Washburn Lab. Nat. Hist., 1, p. 7, 1884; Garman, Bull. Essex Inst., 19, p. 132, 1887 (part?); Cope, Proc. U. S. Nat. Mus., 11, p. 397, 1888; 1939 MEXICAN LIZARDS SMITH 111 Giinther, Biol. Cent.-Amer., Kept. Batr., p. 63, 1890 (part); Cope, Amer. Nat., 30, p. 1009, 1896; Boulenger, Proc. Zool. Soc. Lond., 1897, pp. 489-496, 1897 (part); Cope, Ann. Kept. U. S. Nat. Mus., 4, 1898, pp. 366-367, 1900 (part); Strecker, Trans. Texas Acad. Sci., p. 96, 1902; Ditmars, Kept. Book, pp. 129, 134-135, pi. 44, 1907; Strecker, Proc. Biol. Soc. Wash., 21, p. 47, 1908; idem, p. 72, 1908; idem, p. 168, 1908; idem, Baylor Bull., 12, No. 1, p. 4, 1909; idem, 13, Nos. 4, 5, p. 6, 1910; idem, 18, No. 4, p. 20, 1915; Pratt, Manual Vert. Animals U. S., pp. 198, 199, 1923 (part); Speck, Copeia, 1924, p. 35, 1924; Burt, Trans. Kans. Acad. Sci., 38, pp. 277, 299, 305, 1936; idem, Papers Mich. Acad. Sci., 22, pp. 533, 535-536, 1937; Gaige, Univ. Mich. Stud., Sci., 12, p. 302, 1937. Sceloporus floridanus McLain, Pierson Collec. Kept. Fort Smith, Ark., p. 2, 1899; Prichett, Biol. Bull., 5, pp. 271-277, 285, 1903; Banks, Proc. U. S. Nat. Mus., 28, p. 22, 1904; idem, Proc. Ent. Soc. Wash., 7, p. 134, 1905; Brooks, Trans. Texas Acad. Sci., 8, pp. 23, 25-27, pi. 2, fig. 6, pi. 4, fig. 15, 1906; Hirst, Jour. Linn. Soc., Zool., Lond., 36, p. 200, 1926. Sceloporus thayerii Bocourt, Miss. Sci. Mex., Zool., 3, sec. 1, pp. 176-177, pi. 18, figs. 5, 5 a-b, 1874. Sceloporus undulatus Cope, Proc. Amer. Phil. Soc., 22, pp. 398-399, 1885 (part). Sceloporus spinosus clarkii Boulenger, Cat. Liz. Brit. Mus., 2, p. 227, 1885 (part); idem, 3, p. 503, 1887 (part); Brown, Proc. Acad. Nat. Sci., 55, pp. 546, 552, 556, 1903; Hirst, Jour. Linn. Soc., Zool., Lond., 36, p. 200, 1926. Sceloporus spinosus floridanus Stejneger, N. Amer. Fauna, 7, p. 181, 1893 (part); Bailey, N. Amer. Fauna, 25, pp. 39, 42, 1905; Newman and Patterson, Bull. Texas Univ., Sci., 15, pp. 3-24, figs. 1-13, 1909; Stejneger and Barbour, Check List N. Amer. Amph. Kept., p. 56, 1917 (part); Bequaert, Bull. Amer. Mus. Nat. Hist., 45, p. 295, 1922; Strecker, Bull. Sci. Soc. San Antonio, 4, p. 19, 1922; Stejneger and Barbour, Check List N. Amer. Amph. Kept., 2nd ed., p. 58, 1923 (part); Strecker, Baylor Bull., 27, No. 3, p. 36, 1924; Van Denburgh, Proc. Calif. Acad. Sci., (4), 13, pp. 191, 207-208, 1924; Strecker, Contrib. Baylor Univ. Mus., 2, p. 3, 1926; idem, 6, p. 4, 1926; idem, Copeia, 1927, p. 9, 1927; idem, Contrib. Baylor Univ. Mus., 10, p. 10, 1927; Strecker and Williams, Con- trib. Baylor Univ. Mus., 12, pp. 8, 14, 1927; Strecker, Contrib. Baylor Univ. Mus., 15, pp. 2, 4, 5, 1928; idem, p. 7, 1928; Strecker and Williams, Contrib. Baylor Univ. Mus., 17, p. 15, 1928; Flower, Vert. Animals Zool. Soc. Lond., 3, p. 89, 1929; Strecker, Contrib. Baylor Univ. Mus., 19, p. 12, 1929; idem, 23, pp. 4, 9, 1930; Noble and Bradley, Ann. N. Y. Acad. Sci., 35, pp. 69-70, 1933; Stejneger and Barbour, Check List N. Amer. Amph. Kept., 3rd ed., p. 64, 1933 (part); Strecker, Copeia, 1933, p. 79, 1933; Smith, Trans. Kans. Acad. Sci., 37, pp. 278-279, 1934; Smith and Leonard, Amer. Mid. Nat., 15, p. 192, 1934; Mulaik, Copeia, 1935, p. 156, 1935; Strecker, Baylor Bull., 38, No. 3, p. 32, 1935; Strecker and Johnson, Baylor Bull., 38, No. 3, p. 19, 1935; Ditmars, Kept. N. Amer., p. 48, 1936. Sceloporus spinosus magister Boulenger, Proc. Zool. Soc. Lond., 1897, pp. 495-496, 1897 (part). 112 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 Sceloporus clarkii Stone and Rehn, Proc. Acad. Nat. Sci. Phila., 55, pp. 30, 31, 1903 (part); Cross, Stevens, and Shannon, Okla. Geol. Surv. Circ., 6, p. 34, 1917. Sceloporus spinosus spinosus Brown, Proc. Acad. Nat. Sci. Phila., 55, pp. 553, 556, 1903. Sceloporus olivaceus Smith, Trans. Kans. Acad. Sci., 37, pp. 263, 277-279, 1934; Burt, Trans. Kans. Acad. Sci., 38, p. 277, 1936. Type locality. Arroyo los Olmos, three miles southeast of Rio Grande City, Starr County, Texas. Type EHT 2508, collected by E. H. Taylor and John S. Wright. Distribution. Extreme south-central Oklahoma, southward through central Texas to southern Tamaulipas, central Nuevo Leon, and southeastern Coahuila (fig. 11). Diagnosis. A large species of Sceloporus of the spinosus group, maximum snout-vent measurement 121 mm.; cephalic scales smooth; dorsal scales 28 to 33 from occiput to base of tail, not strongly mucro- nate, keeled, weakly denticulate, in parallel rows, not strongly differentiated from lateral scales; latter two- thirds or three-fourths size of dorsals, their keels, mucrones and denticulations more promi- nent; ventral scales somewhat smaller than laterals, strongly notched, largest on breast; preanal scales as large as median ventral abdomi- nals, largest between series of femoral pores, much larger than scales on posterior surface of thigh; dorsal limb scales no smaller than ventral abdominals, those on hind limb larger; supraoculars five to seven, usually five, separated from median scales by a row of small scales (narrowly in contact in one specimen in 99); supraoculars separated from superciliaries by one complete and usually another incomplete series of scales; frontal usually contacting interparietal; prefrontals usually contacting medially; frontonasal rarely contact- ing frontal; lorilabials usually reduced to one row at some point below subocular; preocular rarely divided; outer row of labiomental scales rarely in contact with mental; first canthal very rarely in contact with lorilabials; second canthal rarely contacting subnasal. Auricular lobules elongate, four or five, the median lobules larger than upper or lower lobules; femoral pores 11 to 16. Tibia longer than head from snout to occiput; fourth toe longer than head from snout to posterior border of ear. Two broad dorsolateral light lines in males, indistinct in females, passing from parietal region to base of tail; a broad darker area between these lines, with irregular, dark, narrow crossbars, some passing through the dorsolateral light lines, more distinct in females; no dark bars on throat; a narrow blue area on each side of abdomen in males, not dark-bordered medially; 1939 MEXICAN LIZARDS SMITH 113 usually some narrow, black lines on ventral surface of thigh, and invariably a narrow black line from gular region down middle of abdomen onto tail. Color. General dorsal ground color (in males) army brown to sorghum brown; a light, sometimes somewhat indefinite, dorso- lateral stripe about two half or one and one-half scale rows wide, passing from neck onto base of tail; between these a broad brownish band, sometimes with indefinite lighter spots scattered over it, occasionally with very indistinct darker brown bands; dorsolateral light stripes broken by narrow crescent-shaped dark bars, which disappear on sides of body and occasionally are visible on median brown band; an irregular dark brown band below dorsolateral light line, originating at posterior corner of eye, where it is very narrow, and continuing above arm, where it becomes broader and more irregular in width, terminating on sides of tail; an indefinite lighter band below this, passing from axilla to groin, interspersed with darker spots; lighter scales in this band frequently with a bluish tinge; below lateral light band, another indefinite narrow dark brown line; a black spot on shoulder, pierced by a light band which originates in upper labial region, passes through ear, then curves downward, passes through black shoulder area, and terminates above arm; limbs with narrow dark bands, the distal edge of each distinct, the proximal edge indefinite; digits also banded; tail with indistinct darker bands. Ventral surfaces dusky; throat suffused with lavender, the posterior central area tinged with pale blue; sides of belly lavender, with numerous scattered spots of pale blue; lateral belly patches not dark-bordered, separated from each other by a broad light band about six scale rows wide medially, wider anteriorly and posteriorly; irregular narrow streaks of dark gray on chest and middle of abdo- men; a similar streak in the midventral line in interfemoral region; ventral surface of thigh with a narrow longitudinal dark streak near insertion, disappearing distally. Dorsal ground color in females light gray or yellow-gray; dorso- lateral light lines indistinct; a series of about eight irregular broad black or dark brown crossbars on back, continuing onto tail, which is distinctly barred; dorsolateral light lines sometimes bordered below by a dark line similar to that in males, except that it is narrow for its entire length; no markings on sides of abdomen; black shoulder spot absent or indistinct; limbs barred as in males, but more dis- tinctly; ventral surfaces immaculate save for narrow dark streaks of 114 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 gray; a median interfemoral dark streak, as in males, and usually one in middle of chest (large females entirely immaculate below). Newman and Patterson (1909) state that in life there are paired spots of blue under the chin in males, and that "faint suggestions of blue are found on the females, but are not noticeable unless careful examination is made." Variation. The following account of variation in cephalic scu- tellation is based on examination of 100 specimens, unless otherwise stated : parietal single in all ; frontoparietal single on each side except in two specimens, in which there are two on one side; frontoparietals in contact medially in 23, separated by an azygous scale in nine; frontal in contact with interparietal in 68; frontal entire in one, the anterior section longitudinally divided in four, the posterior section trans- versely divided in two; superciliaries six or seven (84 counts: 6, eighty-one; 7, three); supraoculars four to seven (194 counts: 4, two; 5, one hundred and twenty-nine; 6, fifty-three; 7, ten) (the speci- men with four has the first supraocular split into several small scales; four enlarged scales follow this) ; one of the supraoculars narrowly in contact with median head scales on one side in three specimens (141 examined); prefrontals in contact medially in 68, separated by an azygous scale in 29; median frontonasal in contact with frontal in two (prefrontals irregular in one); median frontonasal separated from lateral frontonasals on both sides in six, on one side in one; internasals irregular in four, one pair in two, two pairs in 27, one pair with three scales following in nine (42 specimens counted); subnasal present in all; first canthal in contact with lorilabials on both sides in two specimens; first canthal forced above canthal ridge by contact of second canthal and subnasal on both sides in two, on one side in two; two complete rows of lorilabials below subocular on both sides in 14, on one side in 13, reduced to one row by a scale in contact with both subocular and supralabials on one side in 13, on both sides in 73; two loreals on both sides in two, on one side in one (42 counted); two to four postrostrals (43 counts: 2, three; 3, two; 4, thirty-eight); preocular divided on both sides in 12, on one side in nine; outer row of labiomentals in contact with mental on both sides in nine, on one side in six. Dorsal scales 28 to 33, average 29.8 (60 counts: 28, one; 29, twenty-four; 30, nineteen; 31, fifteen; 33, one); ventral scales 40 to 52, average 45.1 (54 counts: 40, one; 41, four; 42, five; 43, nine; 44, seven; 45, five; 46, seven; 47, seven; 48, one; 49, one; 50, five; 52, two); scales around body 30 to 39, average 35.4 (61 counts: 1939 MEXICAN LIZARDS SMITH 115 30, one; 31, one; 32, two; 33, three; 34, eight; 35, seventeen; 36, sixteen; 37, six; 38, four; 39, three). Femoral pores 11 to 16, average 13.3 (197 counts: 11, eight; 12, forty-seven; 13, sixty-four; 14, forty-five; 15, thirty; 16, three). Females attain a greater size than males. The largest male examined measures 97.5 mm. from snout to vent, while the largest female measures 121 mm. There is no definite geographical trend in the above variation. Femoral pore counts of specimens from Tamaulipeca, Tamaulipas, and other localities in Mexico show no trend toward the average in s. spinosus. All specimens have five or more supraoculars and the dorsal scales are not strongly mucronate. None show a tendency toward s. spinosus in coloration. Comparisons. S. olivaceus differs from s. spinosus, of which it usually has been considered a subspecies, in a number of characters which seem to show no tendency toward intergradation. These may be cited as follows: supraoculars five or more (usually four in s. spi- nosus) ; femoral pores more than ten (usually ten or less in s. spinosus) ; gular region never barred (barred in both sexes of s. spinosus); dorsal scales not strongly mucronate (strongly mucronate in s. spi- nosus); lorilabials usually reduced to one row below subocular in olivaceus (two complete rows in s. spinosus) ; median auricular lobules largest (upper lobule or lobules largest in s. spinosus); prefrontals usually in contact medially (usually separated in s. spinosus); females much larger than males (males larger than females in s. spi- nosus; 110 mm. is the greatest snout- vent measurement in females, 118 mm. in males). The differences between olivaceus and undulatus floridanus are difficult to point out. There are no constant differences in scutella- tion. There is very appreciable difference in size, u. floridanus reach- ing a maximum at about 75 or 80 mm. snout to vent (about 121 mm. in olivaceus). There are a number of differences in coloration, the most useful of which is the color of the posterior surface of the thigh. In u. floridanus a broad, dark line is present on the posterior surface of the thigh, and the area above it is frequently mottled. In olivaceus the posterior surface of the thigh is nearly immaculate; a short, narrow dark line is frequently present near the margin of the insertion of hind leg. Adult males are easily distinguished on the basis of ventral and dorsal coloration; in u. floridanus there are no dorso- lateral light lines, and bars are visible on the back. In adult males of olivaceus, the dorsolateral light lines are distinct, and the dorsal 116 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 bars are nearly or quite absent. In males of u. floridanus, the sides of the belly are dark blue, and the patches are closely approximated medially, or confluent; the posterior part of the gular region is black, with small blue patches near the angles of the jaws. S. olivaceus was described under the impression that it represented a species different from the Texas species known at that time as spinosus floridanus. I am at present inclined to agree with Burt (1936), who believes olivaceus to be identical with the Texan "spinosus floridanus" Habits and habitat. In Texas, specimens are almost always found in trees or bushes. Their color blends well with that of the bark of trees and they are undoubtedly frequently overlooked because of this protective coloration. One's attention is frequently attracted to them only by their noisy movements. They are as a rule rather wary, and climb high in the trees to escape danger. If closely pressed they frequently descend into holes in trees. Pritchett (1903) gives an extensive account of laboratory experi- ments in feeding this lizard with a great variety of insects. Verte- brate food (small lizards) is occasionally taken. Specimens were observed drinking by sucking water into the mouth; Newman and Patterson (1909) confirm this observation. Newman and Patterson (1909) give an extensive account of the life history of olivaceus, to which the reader is referred as perhaps the best such work on a lizard of this genus. Specimens are frequently found infested with a red mite described as Geckobiella texana (Banks, Proc. Ent. Soc. Wash., 1904, 7, p. 22). Distribution. Extreme south-central Oklahoma, southward through central Texas to southern Tamaulipas, central Nuevo Leon and southeastern Coahuila. Locality records. OKLAHOMA. LOVE CO.: Near Marietta (KU 15024-6). NEW MEXICO. LINCOLN CO.: Capitan Mts., 9,000 ft. (USNM 44905). TEXAS. ATASCOSA CO.: Pleasanton (KU 15031); Somerset (KU 12470, 15032-4, 15054, 15316-21); Benton (CM 8468). BASTROP CO.: Bastrop (Cragin, 1884). BEXAR CO.: (ANSP 19700); Helotes (KU 15035-46, 15315; ANSP 1243^43); San Antonio (AMNH 44400; FMNH 3468; CAS 31025-8; AMNH 7616, 7633-4, 46048-71, 37364-85; MCZ 4574[2]); 6 mi. S of San Antonio (UMMZ 71008); Leon Springs (CAS 31154-79). BOSQUE CO.: Union Hill and Valley Mills (Strecker, 1928). BROWN CO.: 3 mi. W of Brown- wood (Burt, 1937, p. 536). BURNET CO.: (CM 1016-7; MCZ 7884); Burnet (KU 12632-5; FMNH 1664, 1838; CAS 13106-9). CALHOUN 1939 MEXICAN LIZARDS SMITH 117 CO.: Indianola (Baird, 1859). CALLAHAN CO.: Putnam (Burt, 1937, p. 536). CAMERON CO.: Point Isabel (KU 12640); Brownsville (KU 12642-6; AMNH 22985-6; UMMZ 53984[2], 53985, 53982; FMNH 5494-5, 6835-7, 6871-2; CM 243; AMNH 9420); 4 mi. E of Rio Hondo (UMMZ 74747) ; Los Fresnos Resaca, Brownsville (FMNH 5486-7) ; Laguna del Muerto, Brownsville (FMNH 5488) ; Harlingen (Strecker, 1928); Padre Id. (AMNH 8159). COMAL CO.: 5 mi. NE of New Braunfels (UMMZ 71143). CONCHO CO.: 4 mi. SE of Eden (UMMZ 55310). COOK CO.: Gainesville (KU 12641). DALLAS CO.: 5 mi. SE of Dallas (KU 11394-5); Bachman's Lake, 4 mi. NW of Dallas (MVZ 12519); Dallas (ANSP 13237, 12448-9). DIMMIT CO.: Nueces River, near Carrizo Wells (KU 11708-12); Carrizo Springs (MCZ 8280). DUVAL CO.: San Diego (ANSP 12446). EASTLAND co.: Cisco (KU 15047-52). ELLIS CO.: 8 mi. NE of Midlothian (Burt, 1937, p. 536). EL PASO CO.: El Paso (Burt, 1937, p. 536); Fort Bliss (Van Denburgh, 1924). ERATH CO.: 12 mi. NE of Stephensville (Burt, 1937, p. 536). FALLS co.: Gurley (CAS 33074-5; 1 mi. W of Marlin (CAS 12693). FAYETTE co.: Rutersville (Cope, 1900). FRIO co.: near Pearsall (EHT 222-4). GOLIAD co.: Charco (AMNH 46072-6). GRAYSON CO.: 1 mi. N of Howe (Burt, 1937, p. 536). GUADELUPE CO.: (UMMZ 66734); Seguin (Bailey, 1905). HAYS CO.: San Marcos (AMNH 36980, 32457-65). HIDALGO CO.: McAllen (Burt, 1937, p. 536); 8 mi. S of San Juan (UMMZ 74746, 74751[2]); San Juan (UMMZ 74749) ; Mercedes (CM 194-6) ; Lomita Ranch, 6 mi. N of Hidalgo (Bailey, 1905). HOOD CO.: 5 mi. S of Paluxy (Burt, 1937, p. 536). JACK CO.: Bryson (Burt, 1937, p. 536). JIM WELLS CO.: 6 mi. E of San Diego (EHT 5044-5); 8 mi. NE of Alice (Burt, 1937, p. 536). KARNES CO.: Runge (Burt, 1937, p. 536). KENDALL CO.: 3 mi. N of Waring (Burt, 1937, p. 536); Boerne (Strecker, 1926). KERR CO.: Ingram (Bailey, 1905); 3 mi. W of Comfort (Burt, 1937, p. 536). KINNEY CO.: Ft. Clark (Burt, 1937, p. 536). MCLENNAN co.: Waco (KU 8171-2, 12636-7, 12647-50; UMMZ 42325[2], 42328[3], 70467, 70501; FMNH 1840[8]; LSJU 2189-94; CAS 13098-105, 33078-83; CM 1015, 1008-13); Robinson (CAS 33084-6); Mart (Burt, 1937, p. 536). MATAGORDA CO.: Bay City (CM 189-190). MAVERICK co.: Eagle Pass (KU 15313). MILAM CO.: (Strecker, 1930). NUECES CO.: Corpus Christi (AMNH 1364-5). PALO PINTO CO.: 3 mi. W of Millsap (MVZ 12694); 3 mi. E of Palo Pinto (Burt, 1937, p. 536). REAL CO.: West Frio Canyon (Strecker, 1935). REFUGIO co.: (Strecker, 1908). SAN SABA co.: Brady Creek, 40-50 mi. S of Brownwood (KU 17204-6). SCURRY 118 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 CO.: 21 mi. N of Snyder (UMMZ 70791). SMITH CO.: 5 mi. W of Arp (Burt, 1937, p. 536). SOMERVELL co. : Glen Rose (CAS 33076-7). STARR CO.: (UMMZ 74750[2]); Arroyo Los Olmos, 3 mi. SE of Rio Grande City (KU 15029-30; EHT 2508, 4922-4); Arroyo El Salado, 13 mi. SE of Rio Grande City (KU 15027-8; EHT 4785). SUTTON CO.: 26 mi. SE of Sonora (Burt, 1937, p. 536). TARRANT co.: 1 mi. S of Texas Christian University, near Fort Worth (MVZ 12695). TOM GREEN co.: San Angelo (ANSP 12450-1). TRAVIS co.: Austin (KU 15053; FMNH 23688; ANSP 12445). VALVERDE co.: near mouth of Devil's River (KU 11722-4, 12638); Castle Canyon, 17 mi. SE of Comstock (Burt, 1937, p. 536); Langtry (Bailey, 1905). WEBB co.: Laredo (KU 12639). VICTORIA co.: (Strecker, 1908). WILLACY co.: Raymondsville (UMMZ 54113). WILSON co.: between Polly Ranch and Sutherland Springs (Strecker and Johnson, 1935). ZAPATA CO.: Zapata (EHT 4722-4). NUEVO LE6N: Huasteca Canon, 11 mi. W of Monterrey (EHT 8409A, 8409-12); Sabinas Hidalgo (EHT 8388-9, 8401-5, 13085-6); near Cie"nega de Flores, km. 1030-6 (EHT 8406-8); 31 mi. S of Sabinas Hidalgo (EHT 8453-4); San Diego (USNM 42094); Cade- reyta (USNM 2902); Charco Escondido (USNM 2961 [4]); Monterrey (USNM 46752); Linares (USNM 47610); China (Yarrow, 1883). TAMAULIPAS: 36 mi. N of Limon (EHT 8413); 5 mi. S of Laredo (EHT 8387); Hda. La Clementina, 4 mi. W of Forlon (EHT 8399- 8400); Victoria (USNM 46780); Jaumave (USNM 46729, 46731-2); Matamoros (USNM 9397[6]; MCZ 5944-5; CM 8469); Rancho El Plato, 38 mi. SE of Remosa (USNM 95181); 15 leagues N of Guerrero (USNM 47709); Mier (USNM 47710); La Cruz (FMNH 1291); Tamaulipeca 69243-6[14]); San Jose" (UMMZ 69247); Mulato (UMMZ 69248); Manuel (MCZ 17487-8, 17490); Chocoy (MCZ 17489) ;Tampico (Giinther, 1890). COAHUILA: Saltillo (USNM 47480). ' Sceloporus clarkii clarkii Baird and Girard. Sceloporus clarkii Baird and Girard, Proc. Acad. Nat. Sci. Phila., 6, p. 127, 1852 (part); Dumeril, Arch. Mus. Hist. Nat. Paris, 8, p. 547, 1856; Baird, in Emory, U. S.-Mex. Bound. Surv., 2, pt. 2, No. [3], p. 5, 1859; Cope, Proc. Acad. Nat. Sci. Phila., 1863, p. 105, 1863; Miiller, Reisen Ver. Staaten, Canada, Mex., 3, p. 602, 1865; Cope, Proc. Acad. Nat. Sci. Phila., 1866, pp. 310, 312, 1867; Duges, Naturaleza, 4, p. 30, 1877; Yarrow and Hen- shaw, in Wheeler, Ann. Kept. Geog. Surv. W. 100th Mer., 1878, p. 223, 1878 (part); Cope, Proc. Amer. Phil. Soc., 18, pp. 261, 263, 1879; Cragin, Bull. Washburn Lab. Nat. Hist., 1, p. 7, 1884; Carman, Bull. Essex Inst., 16, p. 17, 1884; Stejneger, N. Amer. Fauna, 3, pp. 110-111, 1890 (part); 1 One specimen (USNM 2325) is said to come from Fort Smith, Arkansas, a record apparently incorrect. 1939 MEXICAN LIZARDS SMITH 119 idem, N. Amer. Fauna, 7, pp. 178-181, pi. 1, figs. 1 a-c, 1893; Cope, Amer. Nat., 30, p. 1014, 1896 (part); Van Denburgh, Proc. Calif. Acad. Sci., (2), 6, pp. 340-341, 1896; Herrick, Bull. Sci. Lab. Denison Univ., 11, p. 126, 1899; Stejneger, N. Amer. Fauna, 14, p. 67, 1899; Cope, Ann. Kept. U. S. Nat. Mus., 1898, pp. 358-363, 1900 (part) ; Stejneger, Proc. U. S. Nat. Mus., 25, p. 150, 1902; Stone and Rehn, Proc. Acad. Nat. Sci. Phila., 55, pp. 30, 31, 1903 (part); Meek, Field Mus. Nat. Hist., Zool. Ser., 7, p. 11, 1905; Mearns, Bull. U. S. Nat. Mus., 56, pt. 1, pp. 104, 107, 110, 123, 126, 132, 1907 (part); Ditmars, Kept. Book, pp. 128, 131-133, 1907 (part); Ruth- ven, Bull. Amer. Mus. Nat. Hist., 23, pp. 533, 537-538, 1907; Ditmars, Kept. World, p. 147, 1910 (part); Stone, Proc. Acad. Nat. Sci. Phila., 63, p. 227, 1911; Van Denburgh and Slevin, Proc. Calif. Acad. Sci., (4), 3, pp. 392, 404, 1913; Riithling, Lorquinia, 1, pp. 14-15, 1916; Stejneger and Barbour, Check List N. Amer. Amph. Rept., p. 53, 1917; Ditmars, Rept. World, revised ed., p. 147, 1922 (part); Van Denburgh, Occ. Papers Calif. Acad. Sci., 10, pp. 359-364, 1922; Stejneger and Barbour, Check List N. Amer. Amph. Rept., 2nd ed., p. 54, 1923; Van Denburgh, Proc. Calif. Acad. Sci., (4), 13, pp. 191, 207, 1924; Ortenburger, Mem. Univ. Mich. Mus., 1, p. 53, 1928; Slevin, Proc. Calif. Acad. Sci., (4), 15, pi. 199, 1926; Burt and Burt, Jour. Wash. Acad. Sci., 19, pp. 450-451, 1929; King, Copeia, 1932, p. 176, 1933; MacCoy, Occ. Papers Bost. Soc. Nat. Hist., 8, pp. 18- 19, 1932; Dury, Proc. Junior Soc. Nat. Hist., Cincinnati, 3, p. 28, 1932; Allen, Occ. Papers Mus. Zool. Univ. Mich., 259, p. 8, 1933; Stejneger and Barbour, Check List N. Amer. Amph. Rept., 3rd ed., p. 60, 1933; Slevin, Handbook Rept. Amph. Pacif. States, pp. 43, 58, 1934; Quaintance, Copeia, 1935, p. 184, 1936; Ditmars, Rept. N. Amer., pp. 47, 50-51, 1936; Gloyd, Program Activ. Chicago Acad. Sci., 8, p. 23, 1937. Sceloporus clarkii clarkii Cope, Bull. U. S. Nat. Mus., 1, pp. 49, 92, 1875 (part); Yarrow, U. S. Geog. Surv. W. 100th Mer., 5, pp. 575-576, 1875 (part); Burt, Trans. Amer. Micr. Soc., 54, p. 172, 1935 (part); idem, Trans. Kans. Acad. Sci., 38, pp. 275, 299, 305, 1936 (part); Taylor, Univ. Kans. Sci. Bull., 24, pp. 477, 483, 1938. Sceloporus spinosus Yarrow, U. S. Geog. Surv. W. 100th Mer., 5, pp. 574-575, 1875 (part); Coues, U. S. Geog. Surv. W. 100th Mer., 5, p. 588, 1875 (part?); Yarrow, Bull. U. S. Nat. Mus., 24, p. 63, 1883 (part?); idem, Smithson. Misc. Collec., 517, p. 10, 1883 (part?); Giinther, Biol. Cent.- Amer., Rept. Batr., p. 63, 1890 (part). Sceloporus clarki clarki Coues, U. S. Geog. Surv. W. 100th Mer., 5, p. 594, pi. 23, fig. 1, 1875 (part); Yarrow, Bull. U. S. Nat. Mus., 24, p. 63, 1883 (part); idem, Smithson. Misc. Collec., 517, p. 11, 1883 (part). Sceloporus couchi Cope, Bull. U. S. Nat. Mus., 17, p. 47, 1880 (?lapsus calami tor clarkii). Sceloporus spinosus clarkii Boulenger, Cat. Liz. Brit. Mus., 2, p. 227, 1885 (part); idem, 3, p. 503, 1887 (part); Stejneger, N. Amer. Fauna, 7, p. 181, 1893; Boulenger, Proc. Zool. Soc. Lond. 1897, pp. 491, 496, 1897 (part); Brown, Proc. Acad. Nat. Sci. Phila., 55, pp. 546, 552, 556, 1903 (part). Sceloporus clarkii Bailey, N. Amer. Fauna, 35, p. 20, 1913; Pratt, Manual Vert. Animals U. S., pp. 198, 199, 1923 (part); Ortenburger and Ortenburger, Proc. Okla. Acad. Sci., 6, p. 107, 1926; Walls, Copeia, 1931, p. 127, 1931. 120 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 Type locality. "Province of Sonora" (= southern Arizona). Cotypes USNM 2940 (3); the specimen with a white tag on its leg is designated the lectotype. Distribution. Southern and central Arizona (excepting the western part of the state), southwestern New Mexico, and Sonora, with the exception of the extreme western and southern parts (fig. 12). FIG. 12. Distribution of Sceloporus orcutti orcutti, A; S. o. licki, V ; S. clarkii clarkii, O; and S. clarki boulengeri, Q. History. The history of clarkii clarkii has been discussed under magister magister. The lectotype has been designated because the other specimens in the cotype series are magister magister. The lectotype apparently had previously been noted to be different from the other specimens, as a white tag has been placed on its leg. Diagnosis. A large species of the spinosus group, maximum snout-vent measurement 130 mm.; dorsal scales 28 to 36, average 31.8; ventral scales 40 to 54, average 46.3; scales around body 32 to 43, average 37.9; femoral pores usually 11 to 16 (rarely 10, except in the southern part of its range, in Sonora), average 12.3; lateral scales gradually decreasing in size toward venter, none of the upper lateral scales larger than median dorsals; one parietal on each side; 1939 MEXICAN LIZARDS SMITH 121 the two posterior supraoculars on each side usually entirely in contact with median head scales; first canthal seldom in contact with lorilabials; outer row of labiomentals rarely in contact with mental; usually three auricular lobules, all short, broad, rounded, the upper much the largest. Back uniform or with narrow, undulate, indistinct bars; nuchal collar narrow, indistinct, frequently broader medially and with an indistinct light border on each side; lower forelimbs with distinct bands; tail with indistinct bands. Description. 1 Head scales smooth, flat, pitted around edges; interparietal about one and three-fourths times as large as either parietal; parietal large, single on each side; one small, subrectangular frontoparietal on each side, rarely two; frontoparietals occasionally in contact medially, usually separated by contact of frontal and interparietal; frontal typically divided, the posterior section some- what smaller than anterior; usually five large supraoculars on each side, the fourth and fifth in contact with median head scales, rarely the fifth partially separated by a small series intercalated along its posterolateral border; a row of small scales between supraoculars and superciliaries, rarely increased to a partially double row, and rarely with small gaps permitting contact of parts of supraoculars with superciliaries; latter usually six, five visible from above; pre- frontals usually in contact, separated occasionally by contact of median frontonasal and frontal or, less frequently, by an azygous scale; frontonasals typical, the median about one and one-half times as large as either lateral frontonasal; usually two distinct pairs of internasals; nasal short, in contact with lorilabials; four postrostrals; subnasal small, rarely absent; first canthal rarely in contact with lorilabials; second canthal usually larger than first; preocular entire; usually two complete rows of lorilabials below sub- ocular; subocular relatively short, followed posteriorly by two post- oculars; three and one-half to four supralabials and four or five infralabials to a point below middle of eye. Mental pentagonal, with a labial border about half that of rostral; outer row or labiomentals rarely in contact with mental; about five postmentals on either side, the anterior scale of either series in contact with its fellow medially; gular scales smooth, all notched except those in extreme anterior part; two notches on scales in posterolateral gular region, others with a single apical notch; median posterior gular scales smaller than adjacent scales; scales in posterior lateral gular region mucronate and keeled. 1 Based on UMMZ 69882, male, Catalina Mountains, Pima County, Arizona. 122 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 Usually three auricular lobules, smooth, more or less rounded, the upper the largest; temporal scales weakly keeled, weakly mucro- nate, denticulate, the largest somewhat smaller than largest scales between ear and lateral nuchal pocket; scales in latter area gradually decreasing in size ventrally, increasing dorsally; a series of very strongly keeled, strongly mucronate scales passing from lower edge of nuchal pocket to a point below ear; scales between nuchal pocket and arm keeled, strongly mucronate, denticulate, the largest sub- equal in size to largest temporal scales, their keels directed ventro- caudad; scales above arm larger, more strongly mucronate, their keels directed dorsocaudad. Dorsal scales not strongly keeled, not strongly mucronate, denticulate (with as many as four denticules on either side of median mucrone) ; dorsals usually in parallel, sometimes slightly convergent rows, the anterior scales smallest, the scales at rump perhaps some- what smaller than median scales; lateral scales more strongly mucro- nate, gradually decreasing in size toward venter, the median laterals about one-half size of median dorsals; ventral scales smooth, the median scales about two-thirds size of median lateral and lateral chest scales, larger than preanal scales; scales on sides of belly and chest, and in gular region, with two apical notches, others with one notch; anterior preanal scales with one notch, posterior scales entire. Dorsal scales of foreleg mucronate, keeled, denticulate, more or less subequal in size, about one-third or one-fourth size of median dorsal scales on body; scales on anteroventral surface of lower foreleg smooth, denticulate, those on posteroventral surface keeled; ventral scales of lower foreleg somewhat smaller than dorsal scales of same member; scales on ventral surface of upper foreleg smooth, notched, gradually increasing in size distally and merging with ventrals of lower foreleg; lamellar formula for fingers 8-11-15-16-11. Dorsal scales of hind leg keeled, mucronate, denticulate, those on shank somewhat larger than those on thigh, and about one-half size of median dorsal scales on body; scales on lower anterior surface of thigh smooth, notched, becoming smaller on ventral surface toward series of femoral pores; the two series of femoral pores separated medially by about eight scales; scales on posterior surface of thigh keeled, mucronate, denticulate, the keels directed upward, the median scales subequal in size to preanal scales; scales on ventral surface of shank smooth, notched, about two-thirds size of dorsal scales of same member; lamellar formula for toes 7-11-17-20-13 (8-11-17-20-14). 1939 MEXICAN LIZARDS SMITH 123 Dorsal caudal scales keeled, mucronate, denticulate, the basal scales somewhat larger than dorsal scales on body; subcaudals smooth and entire except toward tip of tail, where they become keeled, weakly mucronate and denticulate; subcaudals immucronate in females; postanals enlarged in males; no postfemoral dermal pocket. Color. General dorsal ground color in males dark brown to gray brown; light flecks or irregular indistinctly outlined lighter areas scattered over back and sides; an indistinct dark neck band present, broader medially, usually with an indistinct light posterior border, occasionally with a light anterior border; a large irregular bluish or white area in middle of black shoulder patch, sometimes so large as almost to obliterate the black area; flecks of bluish on scales on sides of neck; narrow dark brown lines occasionally present, follow- ing the edges of the lateral scale rows; a narrow dark line, sometimes with an incomplete upper or lower light border, passing from posterior edge of orbit below middle, above ear and to nuchal collar; dorsal surface of tail frequently with numerous vague light blue areas, giving it a bluish cast; tail usually not distinctly barred; limbs with dark gray or dark brown bands, each band with a distinct distal border, but an indistinct proximal border; bands on foreleg very characteristic, more distinct distally; digits barred. The coloration in life is described by Ruthven (1907): "In the males the inferior surface of the limbs and breast, and a narrow band along the middle of the belly, are yellow; the sides of the belly are bright blue, and there is on the throat a spot of very intense blue that fades out to a white or gray anteriorly." Ventral surface of tail sometimes bluish; throat not barred. Females similar to males, except nuchal collar less distinct or absent on back; narrow undulate dark gray or brown crossbars on back, about four or five in number, each bordered posterolaterally by a rather large irregularly outlined light spot; the tail is more distinctly barred than in males; the ventral surfaces are mostly white or cream; sides of belly frequently with some evidence of bluish markings similar to those in males, but much less distinct; gular region with distinct convergent dark brown bars; center of gular area with a large area of pale blue, gradually becoming white anteriorly. MacCoy (1932), referring to specimens collected near Tucson, Arizona, states that "a large, adult female, which has a green spot in the center of each dorsal scale, is decidedly green above." Variation. The following data on variation in cephalic scutella- tion is based on 72 specimens, unless otherwise stated. Parietals 124 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 usually one on each side (212 counts: one, 208; two, 4) ; frontoparietals divided into two on one side in two; frontoparietals contacting medially in 11, fused with frontal in five; frontal contacting inter- parietal in 46, separated by an azygous scale in 18; posterior section of frontal transversely divided in one; prefrontals contacting medially in 47, separated by an azygous scale in seven, by contact of median frontonasal and frontal in 16; first and second canthals fused in one; first canthal fused with subnasal in two; first canthal in contact with lorilabials on both sides in five, on one side in five (178 specimens); preocular divided in none; lorilabials in two com- plete rows below subocular on both sides in 47, on one side in seven, on neither side in 18 (reduced to one row by one or more scales con- tacting both subocular and supralabials) ; first pair of postmentals normally contacting medially, separated in four; outer row of labio- mentals in contact with mental on one side in four, on both sides in four, on neither side in 169. Dorsal scales 28 to 36, average 31.8 (105 counts: 28, one; 29, nine; 30, thirteen; 31, twenty-four; 32, twenty-seven; 33, fifteen; 34, seven; 35, seven; 36, two); ventral scales 40 to 54, average 46.3 (40, two; 41, one; 42, six; 43, ten; 44, five; 45, fifteen; 46, fourteen; 47, sixteen; 48, eleven; 49, thirteen; 50, six; 51, three; 52, one; 54, one); scales around body 32 to 43, average 37.9 (32, one; 33, two; 34, two; 35, eleven; 36, ten; 37, sixteen; 38, fifteen; 39, eighteen; 40, thirteen; 41, twelve; 42, three; 43, one). Femoral pores 10 to 16, average 12.3 (370 counts: 10, thirteen; 11, fifty-seven; 12, one hundred and sixty; 13, one hundred and five; 14, twenty-eight; 15, five; 16, two). All the specimens with 32 to 34 scales around the body are from Sonora. Specimens with 10 femoral pores are predominately from Sonora; nine of the 13 counts of 10 are from Sonora, and four are from Tucson and the Huachuca Mountains. Habits and habitat. There appears to be some disagreement in published notes on the habitat preferred by c. clarkii. According to some authors, trees are preferred; according to others, boulders. In certain localities, where trees are rare, the species would find it neces- sary to live elsewhere, and boulders or rocky areas seem to be preferred to open desert. According to Dr. Edward H. Taylor's observations, in areas in which m. magister and c. clarkii occur together, the habitats are different, the former occupying the desert floor and boulders, and c. clarkii the trees. In areas where m. magister does not occur, c. clarkii extends its habitat to include boulders. It apparently 1939 MEXICAN LIZARDS SMITH 125 finds the desert floor unsuitable. In this case, m. magister seems to be much more restricted in its habitat preference, and maintains its preference regardless of competition of c. clarkii, while the latter is less restricted and can avoid too great competition with m. magister by entering a different ecological niche. Several authors have remarked on habitats in specific localities. Ruthven (1907) states: "In contrast to S. magister, which occurs on the plains, the habitat of S. clarkii is limited to the timber zone along the streams (Willow-Poplar association), and in harmony with the different conditions under which it lives its habits also differ from those of the desert form. It is found only on or near trees, and when surprised does not dash down a hole as would S. magister under the same circumstances, but up and around the trunk, keeping on the far side of the tree like a squirrel. It is thus more arboreal in its habits than S. magister, a fact that determines its local distribution, for trees on the desert are confined to the larger water courses, the higher elevations on the mountains, and the bottoms of the canons. Near Tucson Sceloporus clarkii occurs along the Santa Cruz River and Rillito Creek, following the tributaries of the latter into the canons which they have carved out of the south slope of the Santa Catalina Mountains. In the lower part of Sabino Canon I observed several individuals among the trees and bushes with Cnemidophorus gularis, and they seemed quite as willing when frightened to take refuge beneath the stones that strew the bottom of the gorge as to run up the trees." Van Denburgh and Slevin (1913) record: "At Oracle these lizards were found in cracks in the granite boulders. The one from Mt. Lemon was also taken on a boulder. Nearly all the others were found on trees at Tucson on willows along the Santa Cruz River, in the foothills of the Catalinas on mesquites, in the Huachucas and Chirica- huas on oaks and pines. Those taken at Fairbank were under the eaves of an old adobe barn. They sometimes climb trees to a height of thirty or forty feet." Ortenburger and Ortenburger (1926, p. 107) state, regarding specimens from Steam Pump Ranch, 13 miles north of Tucson, foot of Santa Catalina Mountains: "In no case were they found on the desert floor; all of them were at least a mile up one of the several canyons of the mountains. All except one were seen on the sides of large boulders. In some cases, especially in the cool early morning, they were found in the cracks formed by exfoliation of the huge boulders, the stone evidently retaining some of the heat of the sun- 126 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 shine of the day before. In only one case was a specimen seen on vegetation, and then it was on the trunk of a dead palo verde tree, head down and about one foot from the ground." Ruthven (1907) and MacCoy (1932) record the stomach contents of four specimens. All organic matter consisted of insects, including caterpillars, an ant, two grasshoppers and several beetles. Locality records. NEW MEXICO. CATRON CO.: Pleasanton (USNM 44943); 2^ to 5 mi. N of Glenwood (KU 6489-98, 6500-5, 12299-302, 13125-33, 14913). GRANT CO.: Redrock (USNM 44951); East Canyon (LMK 26085, 26100, 26116-7); 4 mi. N of Silver City (MVZ 7055). HIDALGO CO.: Lordsburg (KU 15305-11). SIERRA CO. : below Hermosa (UMMZ 60037) ; Elephant Butte Dam, Cuchillo (UMMZ 60039). SOCORRO CO.: (KU 7000-1). ARIZONA. COCHISE CO.: Huachuca Mts. (KU 7040, 7090, 12303-4, 12309-12, 12334-9; FMNH 2582; MCZ 14857-63, 29761-5; AMNH 20510, 14901-9, 14911-24, 14926, 14929-35, 14948, 14974, 18639^0, 10643, 18700; CAS 34882-7, 34889-93, 48454-77; LSJU 653^, 656); Montezuma Canyon (UMMZ 53981); Ash Canyon (UMMZ 69871-2; LMK 1639-41); Carr Canyon (UMMZ 69879, 69880[2], 69883; SDSNH 14797-8); Ft. Huachuca (UMMZ 71768[2]; USNM 17782, 19684-6, 21113-4, 22218-22); Miller Canyon (UMMZ 72610-1; SDSNH 14784, 14802); Ramsey Canyon (MCZ 29839-43; SDSNH 14785-96, 14850-1); ridge between Carr and Ramsey canyons (SDSNH 14799-801); Bisbee (USNM 24463; AMNH 290-5); 6 mi. N of Bisbee (UMMZ 69878[2]); 56 mi. N of Bisbee (UMMZ 69870); 8 mi. N of Charleston (UMMZ 69873); Dos Cabezas (UMMZ 71111-3; MVZ 13843); Tombstone (FMNH 918, 1139-40); 4 mi. S of Tombstone (AMNH 36860); 15 mi. W of Tombstone (LMK 4894-6); Portal (USNM 93070-2); Apache (USNM 8494[2]); Rio San Pedro (USNM 20563) ; Boundary Monument 77, San Bernardino Ranch (USNM 21030); 12 mi. N of Willcox (USNM 44572); Chiri- cahua Ranch (USNM 54658); Chiricahua Mts. (LSJU 2156); White- tail Canyon (MVZ 7783-8); Spud Rock Ranger Station (SDSNH 16109); Pinery Canyon (SDSNH 15787-8; MVZ 7782, 7789); Rucker Canyon (LSJU 2118, 2158-60, 2677, 2697); Camp Rucker (USNM 64637); Riggs Home Ranch, Sulphur Springs Valley (MVZ 7790); Fairbank (CAS 35179-83); Paradise (CAS 35005-17); Cave Creek (CAS 35141). GILA CO.: McMillanville (USNM 54597, 54676); Miami (KU 12305-8); Salt River (USNM 54598); San Carlos (USNM 16023). GRAHAM CO.: Fort Grant (USNM 31632); Mt. Graham (USNM 51755-6); Stanley (MVZ 12875). GREENLEE CO.: 1939 MEXICAN LIZARDS SMITH 127 2 mi. below Blue (UCLA 573); Clifton (USNM 51897-9); Eagle Creek (Quaintance, 1935). MARICOPA CO.: Cave Creek (KU 12326- 33); Fish Creek (USNM 54651); Phoenix (KU 10837-8). PIMA CO.: (AMNH 26740, 26719-22); Tucson (UMMZ 65091[2], 64079[5], 64081[4]; MCZ 32130-4; USNM 16961-3, 15745, 16826, 62513, 16935-6, 17240-4; AMNH 2555-6, 2723, 2574-5, 26723; ANSP 11878; SDSNH 11337; CAS 33805-7, 34055-6, 34058-60, 34039-53, 48479-82); 16 mi. N of Tucson (KU 12313-6); 30 mi. S of Tucson (KU 13134-8); Tucson Mts. (AMNH 2497); Steam Pump (AMNH 26694, 26700-2, 26704-6, 26709, 26711, 26714-6); Santa Catalina Mts. (KU 6945, 6951, 7253^4, 12317-24, 15527-43; CAS 34294-301, 34304-8, 34315, 34317, 34685, 48478; UMMZ 69877, 69874); Sabino Canyon (AMNH 453-4; UMMZ 60035-6; SDSNH 14803-10); Canada del Oro (UMMZ 69875); Kelly Ranch, W end of Catalina Mts. (UMMZ 69881, 69882[7]); Ft. Lowell (FMNH 664; CAS 20951-2; LSJU 643, 645-8, 802, 2143^, 2149, 2518, 2521-2, 2524, 2526-7, 2542-3, 2563-4, 2566-9, 2571-3); Rincon Mts. (FMNH 2583); Tanque Verde Ranch (SDSNH 16110-22); Santa Rita Mts. (CAS 48413-53); (?)Baboquivari Mts. (Stone, 1911). FINAL CO.: (USNM 61438); Oracle (LMK 22880-2; CAS 34167-8); Camp Bonito, 8 mi. S of Oracle (UMMZ 69876); Pepper Sauce Canyon, 8 mi. SE of Oracle (UMMZ 72612). SANTA CRUZ CO.: Pefia Blanca Springs (UMMZ 75754[3], 75755-60, 75761[2], 75766; MVZ 20537-8); Tumacacori Mts. (USNM 15748; LMK 5706-7); Mowry, Patagonia Mts. (CAS 33819-23); Santa Rita Range Reserve (USNM 62512); Madera Canyon, Santa Rita Mts. (USNM 61384); Tubac (SDSNH 14811-2, 14821-2, 14824-33, 14835-6, 14838, 14842); Nogales (FMNH 21514); Crittenden (USNM 8484-5). YAVAPAI CO.: Fort Verde (AMNH 1345, 1356-8); Congress Junction (USNM 54663); Montezuma Well (USNM 59794); Jerome (USNM 59800); Beaver Creek (USNM 25479); Yarnell (LMK 8374). SONORA. Nogales (USNM 46840); 32 mi. S of Nogales (USNM 17250-1); 53 mi. S of Nogales (EHT 8343A, 8343-4); 30 mi. S of Noria (EHT 8345); 5 mi. SW of Hermosillo (EHT 8346); 15 mi. N of Hermosillo (EHT 8366; UMMZ 72112-3); 54 mi. SW of Hermosillo (EHT 8347); Guaymas (USNM 13486; LMK 4067); 10 mi. NW of Guaymas (EHT 8348-52); Miramar (EHT 8353-8364); Empalme (EHT 8365); Costa Rica Ranch (MCZ 36883); below Santa Maria Mine, El TigreMts. (UMMZ 78413) ;Pilares (UMMZ 78397[6],78398[4], 78399[3], 78400[2], 78401[3], 78402[2], 78403[2], 78 (UMMZ 78397- 412[43]); Oposura Mts. (MCZ 6763); Kino Bay (SDSNH 16694); 128 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 San Pedro Nolasco Island (LMK 6846; CAS 50516-26); San Pedro Bay (CAS 53413-7); Tiburon Island (Van Denburgh, 1922). Sceloporus clarkii boulengeri Stejneger. Sceloporus spinosus Boulenger, Cat. Liz. Brit. Mus., 2, pp. 217, 266-267, 1885 (part); Giinther, Biol. Cent.-Amer., Kept. Batr., pp. 63-64, 1890 (part); Boettger, Kat. Kept. Senck. Mus., p. 64, 1893. Sceloporus boulengeri Stejneger, N. Amer. Fauna, 7, p. 180, pi. l,figs. 5 a-c, 1893; Van Denburgh, Proc. Calif. Acad. Sci., (2), 6, p. 341, 1896; idem, Proc. Acad. Nat. Sci. Phila., 1897, p. 463, 1898; Stejneger, N. Amer. Fauna, 14, p. 67, 1899; Slevin, Proc. Calif. Acad. Sci., (4), 15, p. 199, 1926; Van Denburgh and Slevin, Proc. Calif. Acad. Sci., (4), 4, pp. 132, 148, 1914. Sceloporus spinosus spinosus Boulenger, Proc. Zool. Soc. Lond., 1897, pp. 491, 494, 496, 1897 (part). Sceloporus clarkii boulengeri Burt, Trans. Amer. Micr. Soc., 54, pp. 171-172, 1935 (part); idem, Trans. Kans. Acad. Sci., 38, p. 275, 1936; Taylor; Kans. Univ. Sci. Bull., 24, pp. 507, 520, 1938. Type locality. Presidio, about fifty miles from Mazatlan, Sinaloa, Mexico. Three cotypes, USNM 14079, collected by A. Forrer. Distribution. Extreme southern Sonora, southward on the Pacific slopes to northern Jalisco (fig. 12). Diagnosis. A large species, maximum snout-vent measurement 120 mm.; essentially similar to clarkii clarkii in scutellation; femoral pores 8 to 11, average 9.1; lorilabials usually not reduced to one row below subocular; frontoparietals frequently in contact medially. Description. 1 Head scales smooth, pitted; interparietal relatively small, pentagonal; parietals single on either side, sub triangular, two-thirds or three-fourths size of interparietal; frontoparietals small, broadly in contact medially; posterior section of frontal one- fourth or one-fifth size of anterior section; prefrontals slightly less than half size of anterior section of frontal, broadly in contact medially; three frontonasals, the median somewhat larger than others, the lateral scales subequal in size to either prefrontal, in contact with both canthals; two large pairs of internasals, the anterior pair separated from nasal by a series of small scales, both pairs separated from first canthal by a single small scale; supraoculars five-five, the anterior the smallest, the others subequal in size, the third slightly larger; a series of small scales between supraoculars and median head scales extending from second canthal slightly beyond suture between fourth and fifth supraoculars; a small scale intercalated between last supraocular and parietal, at the extreme outer edge; 1 Based on EHT 681, male, topotype. 1939 MEXICAN LIZARDS SMITH 129 first supraocular in contact with first superciliary; a series of small scales intercalated between superciliaries and supraoculars extending from posterior edge of first supraocular to posterior edge of fifth; five superciliaries visible from above; two canthals, the second forming a small portion of the superciliary ridge, the first not touch- ing the lorilabials; subnasal small; nasal in contact with lorilabials, separated from rostral; preocular completely divided on one side, only partially divided on other (abnormal); two canthals on one side, irregular on other; subocular normal; two strongly keeled postoculars following subocular posteriorly; two rows of lorilabials, not reduced to one below subocular; four supralabials and five infralabials to a point below middle of eye. Mental subtriangular, with a labial border two-thirds that of rostral; three pairs of fairly well-differentiated postmentals, the scales of the anterior pair in contact medially; outer row of labio- mental scales separated from mental by partial contact of first infralabial and first postmental; inner row of labiomentals absent (abnormal); gular scales subequal in size, smaller anteriorly, with one or two (usually one) apical notches; scales below ear with weak keels, somewhat mucronate; scales in gular fold region usually with two apical notches. Auricular lobules three-four, the upper the largest, all smooth, somewhat acuminate; largest auricular lobule subequal in size to largest of preceding scales; temporal scales very weakly keeled, not or very weakly mucronate, somewhat smaller than largest scales between ear and lateral nuchal fold; scales surmounting lateral nuchal pocket keeled and strongly mucronate, these scales extending along a ridge continuous to a point below ear opening; scales between lateral nuchal fold and arm insertion mucronate, denticulate, very weakly keeled, somewhat larger than gular scales. Scales on nape weakly keeled, weakly mucronate, somewhat smaller in size than those following them; dorsal scales keeled, rather strongly mucronate, denticulate, in convergent rows; lateral scales in diagonal rows, about one-half size of, and more strongly keeled, mucronate and denticulate than dorsal scales; ventral scales smooth, with one or two apical notches, about one-half or two-fifths size of dorsal scales; scales in interfemoral region reduced in size, somewhat larger than or subequal in size to preanal scales; latter not notched; scales on chest somewhat larger than following scales; dorsal scales on rump somewhat larger than preceding scales; basal caudals on dorsal surface approximately as large as dorsal scales 130 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 on body, strongly keeled and mucronate, weakly denticulate, becom- ing smaller distally; subcaudals smooth and rounded at base of tail, becoming keeled and weakly mucronate toward tip of tail; enlarged postanal scales present, separated from each other by two small scales. Dorsal scales of foreleg weakly keeled, mucronate, weakly denticu- late, those on upper foreleg about one-half size of dorsal scales on body, one-third larger than dorsals on lower foreleg; dorsal scales on elbow greatly reduced in size, approximately one-third or one- fourth size of scales on lower foreleg; ventral scales of lower foreleg subequal in size to dorsal scales of same member, notched, smooth anteriorly, keeled posteriorly and toward hand; ventral scales of upper foreleg smooth, notched, very small toward axilla, increasing in size toward lower foreleg; lamellar formula for fingers 9-12-16- 18-12 (9-13-15-18-13). Dorsal scales of shank and thigh subequal in size, about as large as dorsal scales of upper foreleg, keeled, mucronate, not or weakly denticulate; scales at knee smaller; ventral scales of shank subequal in size to dorsal scales of same member, rounded, smooth, becoming keeled toward foot; scales on anterior surface of thigh very weakly keeled and mucronate, becoming smooth, rounded and smaller toward series of femoral pores; all scales on posterior surface of femur much smaller than preanal scales, those in a central area keeled and mu- cronate; lamellar formula for toes 8-12-18-20-14 (8-12-18-20-15). Color. The coloration is much as in clarkii clarkii. Females are most distinctively marked. The black collar is present, not confluent ventrally, but frequently complete dorsally. Usually the collar is about one scale wide, but may be broader, with a light posterior edge on middle of back. The collar is confluent with a median dark band three and two half scale rows wide, which passes onto the tail. The edges of the median band may be emarginate, with light borders on the posterior oblique edges of the emarginations. A tan-colored band about two half scale rows wide passes from the collar along each side of the median dark band onto the tail. Lateral to this on each side is a dark band similar in color to the median band, passing from above the axilla to the groin. Below this is another tan band, sometimes broken irregularly, passing from the axilla to the groin, and below this is still another dark, slate-colored band merging ventrally with the cream color of the abdomen. The head is straw color. The throat is slate-colored, with a light to dark blue central gular area, with a lighter medial streak about two scales 1939 MEXICAN LIZARDS SMITH 131 wide. The limbs have transverse bands dorsally of slate and straw color, the lighter bands the narrower, and the darker bands with their distal edges more distinct than their proximal edges. The tail is faintly or distinctly banded with the same colors. Males have a more or less similar coloration when young, but later in life become more or less uniform light straw color above. Dark blue lateral abdominal areas are present, bordered medially by black areas confluent medially and extending into the groin. The throat is black, except for the cream-colored mental region, with a large median blue spot. The black shoulder patches may or may not unite dorsally, but are always confluent ventrally. Variation. The variation in scutellation of the head in 52 speci- mens (unless otherwise stated) is as follows: parietal single in all; frontoparietals single in all, in contact medially in 16, separated by an azygous scale in eight; frontal in contact with interparietal in 27; posterior section of frontal longitudinally divided in one, anterior section divided into three scales in one, into two scales in one; superciliaries five to seven (36 counts: 5, one; 6, thirty- three; 7, two); supraoculars four to six (36 counts: 4, one; 5, thirty-two; 6, three); only last supraocular in contact with median head scales in 28, last two in 46, last three in two (76 counts); prefrontals in contact in 27, separated by an azygous scale in six, by contact of median frontonasal with frontal in five (36 counts) ; median fronto- nasal separated from lateral frontonasals on one side in one, normal in others; two pairs of internasals in 18 counts; canthals fused on both sides in seven, on one side in one (38 counted); first canthal forced above canthal ridge by contact of subnasal and second canthal on both sides in eight, on one side in five (38 counts); preocular divided on both sides in three, on one side in one (38 counts) ; two loreals present on both sides in three, none in one (by fusion with first canthal on one side, with subnasal on other) (38 counts) ; four post- rostrals in 18 out of 52; two complete rows of lorilabials below subocular on one side in five specimens, on both sides in 39; lorilabials reduced to a single row below subocular by a single scale in contact with both subocular and supralabials on one side in five, on both sides in eight (52 counts) ; outer row of labiomentals in contact with mental in none. Dorsal scales 27 to 32, average 29.8 (52 counts: 27, two; 28, seven; 29, eleven; 30, eighteen; 31, nine; 32, five); ventral scales 39 to 51, average 44.2 (34 counts: 39, one; 40, two; 41, three; 42, seven; 43, two; 44, three; 45, eight; 46, two; 47, two; 50, two; 51, 132 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 two); scales around body 31 to 41, average 34.4 (35 counts: 31, one; 32, five; 33, seven; 34, eight; 35, six; 36, three; 37, two; 38, two; 41, one). Femoral pores 8 to 11, average 9. 1 1 (181 counts: 8, thirty- nine; 9, eighty-five; 10, fifty- two; 11, five). There is little geographical correlation in the above data. Speci- mens from Isabel Island show a strong tendency to have a single row of lorilabials below subocular (17 out of 18 counts), while specimens from the mainland show a very slight tendency (10 out of 86 counts). In the absence of other corroborative evidence of subspeciation, it appears wisest to regard these populations as the same subspecies. Specimens from the southern part of the range show a smaller average number of femoral pores, but the maximum number, 11, is well scattered throughout the range. Specimens with this count have been examined from Hostotipaquillo, Isabel Island, Mazatlan and San Francisquito. Comparison. S. clarkii boulengeri is most closely related to clarkii clarkii, from which it differs in certain characters of colora- tion, and in three scale characters, of which the femoral pore count is the most significant. c. boulengeri c. clarkii Per cent Per cent Pores 10 or less 97.2(181) 3.8(370) Frontoparietals contact medially 30.8 (52) 15.3 (72) Two complete rows of lorilabials below subocular 79.9(104) 70.1(144) Females of c. boulengeri differ from those of c. clarkii in having the femoral pores decreasing in size distally; frequently the distal pores are very indistinct, while the proximal three or four are very distinct, and careful examination is necessary to discern the actual number. Habits and habitat. Slevin (1926, p. 199) states that this sub- species is "abundant on Isabel Island and found mostly on the small trees back of the landing place. It is strictly an arboreal species and in habits resembles Sceloporus clarkii, its northern relative." Locality records. SONORA: Alamos (MCZ 1) Agiabampo (LMK 4069). SINALOA: (AMNH 1366-71); Mazatlan (AMNH 20680-90, 20716-7, 15499-509; USNM 51382-3; LMK 7337^1; LSJU 2895- 901, 2903-^, 2910, 2913-9, 2923, 3523); 9 mi. S of Mazatlan (EHT 8378-84); 1 mi. E of Mazatlan (EHT 8385); Presidio, 50 mi. S of Mazatlan (EHT 8367-77, 8386; USNM 14079[3]); San Francisquito (AMNH 15494); Rincon de Urias (AMNH 20714-5, 20691-2); Escuinapa (AMNH 15534); Mocorito (MCZ 27084); Sierra de Choix 1 Part of these data taken from Slevin (1926). 1939 MEXICAN LIZARDS SMITH 133 (USNM 47418); Bacubirito (USNM 33574-6); Rosario (USNM 47679-80); Los Mochis (USNM 56856). NAYARIT: Rosamorada (AMNH 15498, 19351-3, 19355); Puerta Azul, E of Santiago Escuintla (AMNH 19354); N of Santiago Escuintla (AMNH 19052); Isabel Island (MCZ 22548; USNM 24646-51, 71669-70; UMMZ 70789; LMK 26780, 7332-4, 10125-9; CAS 59073-153); Tepic (Van Denburgh, 1897); Acaponeta (USNM 47673-5). JALISCO: W brink of Arroyo Hondo, Hostotipaquillo (AMNH 15519). Sceloporus orcutti orcutti Stejneger. Sceloporus orcutti Stejneger, N. Amer. Fauna, 7, p. 181, pi. 1, figs. 4 a-c, 1893; Boulenger, Proc. Zool. Soc. Lond., 1894, p. 724, 1894; Van Denburgh, Proc. Calif. Acad. Sci., (2), 5, pp. 83, 113, 1895; Cope, Amer. Nat., 30, p. 1017, 1896; Van Denburgh, Proc. Calif. Acad. Sci., (2), 5, pp. 1004, 1005, 1896; Boulenger, Proc. Zool. Soc. Lond., 1897, pp. 488-489, 1897; Van Denburgh, Occ. Papers Calif. Acad. Sci., 5, pp. 13, 15, 74, 86-89, 1897; McLain, Collec. Herp. Western Coast U. S., p. 8, 1899; Cope, Ann. Kept. U. S. Nat. Mus., 1898, pp. 354-356, 1900; Meek, Field Mus. Nat. Hist., Zool. Ser., 7, p. 11, 1905; Ditmars, Kept. Book, pp. 128, 133-134, 1907; Mearns, Bull. U. S. Nat. Mus., pt. 1, 56, pp. 133, 138, 1907; Van Den- burgh, Proc. Calif. Acad. Sci., (4), 3, pp. 149, 150, 151, 152, 1912; Atsatt, Univ. Calif. Publ., Zool., 12, pp. 37-38, 46, 47, 48, 49, 1913; Grinnell and Camp, Univ. Calif. Publ., Zool., 17, p. 163, fig. 7, 1917; Stejneger and Barbour, Check List N. Amer. Amph. Kept., p. 56, 1917; Hall and Grin- nell, Proc. Calif. Acad. Sci., (4), 9, p. 54, 1919; Stephens, Trans. San Diego Soc. Nat. Hist., 3, p. 62, 1921; Van Denburgh and Slevin, Proc. Calif. Acad. Sci., (4), 11, pp. 51, 61, 1921; Nelson, Mem. Nat. Acad. Sci., 16, pp. 114, 130*1922; Schmidt, Bull. Amer. Mus. Nat. Hist., 46, pp. 662-663, 1922; Van Denburgh, Occ. Papers Calif. Acad. Sci., 10, pp. 352-356, pi. 28, 1922; Stejneger and Barbour, Check List N. Amer. Amph. Kept., 2nd ed., p. 58, 1923; Klauber, Copeia, 1926, p. 116, 1926; idem, Zool. Soc. San Diego, Bull. 4, p. 3, 1928; Burt and Burt, Jour. Wash. Acad. Sci., 19, p. 452, 1929; Klauber, Copeia, 1929, p. 17, 1929; Bogert, Bull. S. Calif. Acad. Sci., 19, p. 7, 1930; Klauber, Zool. Soc. San Diego, Bull. 5, p. 3, 1930; idem, 8, pp. 47, 75, 80, 1931; Wright and Wright, Copeia, 1931, p. 84, 1931; Linsdale, Univ. Calif. Publ. Zool., 38, p. 367, 1932 (part); Burt, Amer. Mid. Nat., 14, p. 238, 1933; Stejneger and Barbour, Check List N. Amer. Amph. Kept., 3rd ed., p. 64, 1933; Klauber, Zool. Soc. San Diego, Bull. 11, p. 12, 1934; Slevin, Handb. Kept. Amph. Pacif. States, pp. 44, 52, 1934; Burt, Trans. Kans. Acad. Sci., 38, pp. 276, 277, 299, 305, fig. 61, 1936; Ditmars, Kept. N. Amer., p. 47, 1936. Sceloporus digueti Mocquard, Nouv. Arch. Mus. Hist. Nat. Paris, (4), 1, pp. 311-313, pi. 13, figs. 2, 2 a, 2 6, 1899 Santa Rosalia, Lower California. Sceloporus magister rufidorsum Linsdale, Univ. Calif. Publ., Zool., 38, p. 366, 1932 (part). Type locality. Milquatay Valley, San Diego County, California. Type USNM 16330, collected by C. R. Orcutt. 134 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 Distribution. California, from southern San Bernardino County southward into Lower California to the Sierra de la Gigantea, and on some adjacent islands in the Gulf of California (fig. 12). Diagnosis. A species of moderate size, maximum snout-vent measurement 109 mm.; dorsal scales 29 to 36, average 32.3; ventral scales 36 to 44, average 40.6; scales around body 29 to 37, average 33.6; femoral pores 10 to 15, average 13.1; labiomental scales separated from mental; first canthal usually touching lorilabials; auricular lobules five or six, rounded, notched (pointed in Lower California specimens), the median ones not distinctly longer or larger than the upper ones; dorsal scales very weakly keeled, in convergent rows, with a relatively deep notch on either side of the short terminal mucrone; caudal scales very strongly mucronate, weakly keeled (except distally); supraoculars five, the last two in contact with median head scales; usually two complete rows of lorilabials below subocular. Adult males usually with one or more light spots on each scale on back and sides; belly and throat in adult males entirely bluish; young and females with broad brown bands on back, separated by narrow light bands. Description.* Head scales smooth, pitted; two parietals, the posterior narrow, the anterior subtriangular; interparietal pentagonal, about twice as large as either anterior parietal ; frontoparietals single on each side; frontal usually touching interparietal, seldom separated by an azygous scale or by contact of frontoparietals; frontal normally divided; six superciliaries, five visible from above; five supraoculars, the fourth and fifth in contact with median head scales; row of scales between supraoculars and median head scales terminating at suture between third and fourth supraoculars; a single scale inserted at posterior margin of fifth supraocular; one complete row of small scales between supraoculars and superciliaries, occasionally with one or two extra scales; prefrontals in contact; frontonasals typical; nasal separated from rostral by three or four, usually four, postros- trals; internasals irregular or in two or three pairs, the scales some- times variously fused; subnasal usually present, sometimes absent; canthals two; first canthal usually touching lorilabials; usually lorilabials reduced to one row below subocular by one scale in contact with both subocular and supralabials; two rows of lorilabials in loreal region; one loreal; preocular entire; two strongly keeled postoculars; four supralabials and four and one-half infralabials to a point below middle of eye. 1 Based on UMMZ 57500, male, Campo, San Diego County, California. 1939 MEXICAN LIZARDS SMITH 135 Mental pentagonal, with a labial border about two-thirds that of rostral; four or five pairs of postmentals, the scales of the anterior pair in contact medially, the others separated; outer row of labio- mentals separated from mental by partial contact of first postmental and first infralabial; most of gular scales with a single notch, the posterior ones more strongly notched, the anterior scales weakly notched or entire; median posterior and lateral gular scales, except those immediately below ear and near angle of jaws, somewhat larger than others; some of scales in gular fold region with two notches. Auricular lobules usually five, usually elongate, extending over ear, pointed, smooth, the median ones largest, larger than preceding scales; temporal scales very faintly keeled or smooth, mucronate, denticulate, smaller than scales between ear and lateral nuchal pocket; latter scales strongly mucronate and denticulate, keeled toward their apices; lower scales between arm and nuchal pocket strongly notched, denticulate, the upper scales becoming strongly mucronate and weakly keeled toward apex. Dorsal scales not or weakly mucronate, strongly denticulate, smooth or very weakly keeled, in convergent rows; lateral scales strongly mucronate, weakly keeled toward apices, about two-thirds or three-fourths size of dorsal scales; ventral scales smooth, notched, some toward sides of belly with two notches; preanal scales smaller than abdominal scales, rounded. Dorsal scales of foreleg strongly mucronate, strongly denticulate, keeled toward apex,.subequal in size (except those on hand), about one-half size of dorsal scales on body; scales on ventral surface of lower foreleg about two-thirds size of dorsals of same member, those toward anterior surface smooth; scales in axilla very small, gradually increasing in size on upper forearm toward lower foreleg; ventral scales of upper foreleg smooth, notched; lamellar formula for fingers 9-13-17-18-12 (8-12-16-17-12). Dorsal scales of hind leg strongly mucronate, denticulate, keeled toward apex, those on shank and thigh subequal in size, somewhat larger than dorsal scales of foreleg; scales on lower anterior and ventral surfaces of thigh smooth, notched, decreasing in size toward series of femoral pores; scales on posterior surface of thigh strongly keeled, the keels directed upward, largest medially, the largest somewhat larger than preanal scales; ventral scales of shank smooth, notched, as large as dorsal scales of same member; lamellar formula for toes 7-12-19-20-15. 136 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 Dorsal scales of tail very strongly mucronate, denticulate, weakly keeled, subequal in size to dorsal scales on back; ventral scales smooth except near tail, irregularly notched; postanals enlarged in males; no postfemoral dermal pocket. Color. General ground color in males coppery; a blue spot in the center of each scale on back, neck, limbs, sides of body, neck, and head; scales on sides of body with an additional small blue spot on each side of the larger median spot; a light yellowish spot on most dorsal head scales; a black shoulder patch, with some small, bluish spots scattered through it; entire ventral surface of head, body, and limbs cyanine blue; most of the scales of the throat and abdomen edged with black or rusty brown; the dark edges of the gular scales extensive, reducing the central blue area to small size; ventral surface of tail bluish. Females variable in dorsal color pattern; usually more or less of a banded pattern evident; some with very distinct alternating light and dark bands, the lighter bands somewhat narrower; limbs and tail frequently distinctly banded, the light bands with a bluish tinge. Ventral surfaces immaculate, sometimes with faint bands across the abdomen and tail, the bands confluent with the dorsal bands; ventral surfaces sometimes tinged with pale blue. Young with numerous alternating dark and light brown bands, much as in females. Specimens from the southern part of the range of o. orcutti are less distinctly barred in the females and young, and the males are less spotted. Variation. The variation in cephalic scutellation of 51 speci- mens is as follows: two parietals on each side in all; frontoparietals single in all; frontal touches interparietal in 35, separated by an azygous scale in eight, by contact of frontoparietals in eight; frontal entire in one; superciliaries five to seven (5, four; 6, forty-three; 7, four); six supraoculars on one side in two, five in others; two posterior supraoculars contact median head scales in all except one, in which all except the first are in contact; prefrontals in contact medially in all but one, in which an azygous scale separates them; frontonasals normal in all; internasals rather irregular, usually in one to three pairs; subnasal absent on both sides in three, on one side in two; first canthal separated from lorilabials on both sides in seven, on one side in three; preocular divided on both sides in four, on one side in five; one loreal in all; three postrostrals in one, four in others; lorilabials reduced to one row below subocular by a scale in contact 1939 MEXICAN LIZARDS SMITH 137 with both subocular and supralabials on one side in 11, on both sides in four; outer row of labiomentals contacts mental in one. Dorsal scales 28 to 36, average 32.3 (50 counts: 28, one; 29, five; 30, one; 31, seven; 32, ten; 33, sixteen; 34, five; 35, four; 36, one); ventral scales 36 to 44, average 40.6 (49 counts: 36, two; 37, three; 38, five; 39, six; 40, four; 41, ten; 42, nine; 43, six; 44, four); scales around body 29 to 37, average 33.6 (50 counts: 29, one; 30, three; 31, five; 32, six; 33, four; 34, twelve; 35, eleven; 36, seven; 37, one). Femoral pores 10 to 15, average 13.1 (99 counts: 10, three; 11, ten; 12, eighteen; 13, twenty-five; 14, twenty- eight; 15, fifteen). Comparisons. The selection of key characters to separate S. o. orcutti and S. m. magister is difficult despite the numerous minor differences between the two. There seems to be no single character which serves infallibly to separate them. S. o. orcutti in Lower California differs from m. rufidorsum and m. monserratensis in three characters. These forms usually have six or more supraoculars, femoral pores usually sixteen or more, and labiomental scales in con- tact with mental. Differences between m. magister and California o. orcutti are: labiomental scales in contact with mental in m. magister, separated in o. orcutti (with rare exceptions in both); median dorsal scales with a relatively deep notch on either side of median mucrone in o. orcutti, not in m. magister; auricular lobules pointed in m. magister, the median ones largest, while in o. orcutti the auricular lobules tend to be rounded or notched and not so narrow, and the median ones are not distinctly larger than the upper; the shoulder patch is distinct in m. magister, indistinct or absent in o. orcutti; the dorsal scales in males of o. orcutti have light longitudinal streaks, not in m. magister; the entire ventral surfaces are dark blue in adult males of o. orcutti, not in m. magister. Specimens from Lower California frequently differ from the California specimens by having the lateral belly patches separate in males, the middle of the throat blue, the chest white, the limbs white except on the anterior surface of thigh, labia and anterior part of gular region faintly barred; sides of head and neck not spotted. The dorsal scales and scales around the body average fewer; the femoral pores are slightly less numerous; there are more frequently two complete rows of lorilabials below subocular. Habits and habitat. Van Denburgh (1922, pp. 355-356) states: "This lizard of the rocks is common near San Jacinto, but is very 138 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 timid, rarely permitting the collector to approach near enough to use fine shot with deadly effect. In the cool of the morning and late in the afternoon it may be seen upon the highest point of some rounded boulder, but during the warmer hours it avoids the direct rays of the sun, and must be sought on the shady sides of the granite, into whose crevices it quickly disappears when approached too closely. Miss Atsatt [1913, p. 38] writes: The grotesque large black males with their bulldog-like pose, the gaudily colored males of medium size, the paler cross-barred females and juveniles are inseparably associated with the foothills and lower areas of San Jacinto. Their wildness or shyness seems to vary with localities. Generally in the late afternoon the males are very bold and will calmly await approach within a few feet.' ' Linsdale (1932, p. 367) states: "Twenty-two of the thirty speci- mens of this species were obtained from rocks. They were either perched on the tops or clinging to the sides of the boulders. Most of the places were at the margins of meadows, close to streams, or on canyon walls. Other places of capture were as follows: on willow limb at edge of swampy ground; in mouse trap under a 'tuna cactus'; on rocky ledge under a shrub; on the ground in an old corral; picked up by hand in early morning in a trail." Klauber (1926, p. 116) states that specimens are found at times under flakes attached to boulders. Locality records. CALIFORNIA. SAN BERNARDINO CO.: (LAM 675; AMNH 20645-6); (?) San Bernardino Mts. (LSJU 5574-81); Reche Canyon near Colton (MVZ 68-74, 6280); Waterman Canyon, San Bernardino Mts. (Van Denburgh, 1922). RIVERSIDE CO.: (USNM 54794-805); Cahuilla Valley (LSJU 861-7, 869-77, 879-94, 896-7); Riverside (FMNH 668, 704); 4 mi. SE of Riverside (UMMZ 72655; CAS 47815-30; MCZ 15579); 5 mi. S of Riverside (SDSNH 12310-3); Palm Springs (UMMZ 70787; CAS 35376-9; MVZ 7047- 9); Tahquitz Canyon (UCLA 285, 303); San Jacinto Mts. (UCLA 446; USNM 44843); San Jacinto (LSJU 804-12, 815, 817, 821-39, 840-60, 595, 898, 5935-47; USNM 21165); Andreas Canyon (CAS 43204-5; LAM 295-6; USNM 69754-6); Keen Camp (CAS 43063- 6); Fuller's Mill, 5,900 ft. (MVZ 288); Schain's Ranch, 4,800 ft. to 5,100 ft. (MVZ 289, 324); Hemet Lake, 4,400 ft. (MVZ 508); Poppet Flat, 4,100 ft. (MVZ 325); Kenworthy, 4,500 ft. (MVZ 566-9); Kenworthy Valley (LMK 20696); Palm Canyon, 3,000 ft. (MVZ 250; LAM 391-3); Pinyon Flat (UCLA 479); Gavilan (LSJU 5500-1, 5576, 5481, 5468, 5493); Perris Valley (LSJU 5601-14); Perris (CAS 1939 MEXICAN LIZARDS SMITH 139 57783; MCZ 34104); 2^ mi. SW of Ferris (CAS 57782); 7 mi. SW of Ferris (CAS 64642); Temescal (LSJU 3299); Temescal Mts. (Van Denburgh, 1922); 5 mi. NE of Elsinore (CAS 57786-93); Elsinore (SDSNH 12314-5); 2 mi. S of Elsinore (USNM 87029-30); Hemet (CM 6286-7); 4 mi. W of Hemet (CAS 57758-63); 6 mi. W of Hemet (CAS 57778); 8 mi. W of Hemet (CAS 57779); Hemet Valley (CAS 20946); 3 mi. E of Hemet (LAM 797[2]); Hall Grade near Cabezon (MVZ 9, 127, 129, 171); Cabezon (MVZ 8, 10-11, 128, 130, 208, 6143^); Banning (MVZ 12, 113-5, 165, 189; USNM 45038-9, 75139); Snow Creek, 1,500 ft. to 2,000 ft., near Whitewater (MVZ 80-83, 160-4, 6145-9, 6151; UCLA 598-9); Whitewater, 1,816 ft. (MVZ 6150); Carrizo Creek, 3,000 ft. (MVZ 251, 489); Dos Palmas Spring (MVZ 570); Beaumont, 2,500 ft. (MVZ 6153); Idyllwild, 6,000 ft. (MVZ 6152); Moreno (LMK 2793; SDSNH 11935); Temecula (LMK 7504); Winchester (LMK 7505); Auld (LMK 7506-7) ; Asbestos Spring (LMK 20697) ; Gulp Valley (SDSNH 14048-52); Box Spring (SDSNH 11209); Corona (LAM 306); Mockingbird Canyon (LAM 42); Mt. Rubidon (USNM 68749); Mur- ray Canyon (Van Denburgh, 1922) ; Lamb Canyon (Van Denburgh, 1922). SAN DIEGO CO.: (LSJU 900-6, 908-11, 913-7; USNM 21918- 30, 58693); Campo (UMMZ 57500; CAS 40310-3, 58162-8; AMNH 20479); between Campo and coast (LSJU 922); La Puerta Valley (MVZ 9237); La Puerta (SDSNH 11201, 11210-2, 11511); Jacumba (LMK 491, 512, 2664; USNM 53680-1); 2-3 mi. E of Jacumba (UMMZ 69890; LMK 1293); San Diego (FMNH 666; ANSP 12463); Boulder Park (UMMZ 71150) ; Mountain Spring (UCLA 43; SDSNH 14043); Strawberry Valley (LSJU 918-20); Clogstone Valley (LSJU 921); Chihuahua Mts. (LSJU 5719-21, 5729, 5736); Dulzura (CAS 64328; LMK 609, 24977); 5 mi. S of Hodges Lake (CAS 58145-7); La Posta (CAS 64520); San Felipe Creek (CAS 62788-92); Sentenac Canyon (CAS 64545; LMK 523, 24978-9; MCZ 20519); Viejas (CAS 64506); Wynola (CAS 64392); Escondido (MVZ 836-7); 7 mi. S of Escondido (AMNH 36843); Pine Mt. (MVZ 838-42) ; Japatul (LMK 182) ; Descanso (LMK 187) ; Clover Flat (LMK 617) ; Ramona (LMK 710; SDSNH 15883, 16820); between Ramona and Ballena (LMK 1017); between Pala and Bonsall (LMK 1769); El Capitan (LMK 21222-30); Hipass (LMK 24976-7); Jamul (SDSNH 14047, 16503); Montezuma Valley (SDSNH 14169, 14044); Morena Dam (SDSNH 11880-1); Borego Palm Canyon (SDSNH 11943); Poway (SDSNH 13325); Foster (SDSNH 14045); Milquatay Valley (USNM 16328- 36); Witch Creek, Santa Isabel (USNM 20214-29, 20345-9, 20386- 140 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 90); Oak Grove, Henshaw Dam, Viejas Grade (Van Denburgh, 1922). ' LOWER CALIFORNIA. Agua de las Fresas (FMNH 1143); An- geles Bay (Van Denburgh, 1922); Arroyo Calentura (LMK 6102); Canon Esperanza (FMNH 1067, 1058[3]); Carmen Island (CAS 51815-32, 51924-30; LMK 4043-4); Catavina (MVZ 13577-86); 10 mi. N of Catavifia (SDSNH 15513); Comondu (MVZ 13587-8, 13591-2) ; Coronados Island, near Carmen (CAS 51757-62) ; El Cajon Canon (MVZ 19601-8); 2 mi. E of Ensenada (CAS 57571); between Ensenada and San Rafael Valley (LSJU 705); Ildefonso Island (CAS 51718-28; LMK 4045-6, 6843); La Grulla (MVZ 9748); Laguna Hansen (MVZ 10482-3; LMK 20306-7, 23109); La Joya, San Pedro Martir Mts. (CAS 56886-95) ; 2 mi. S of La Joya (CAS 57337, 57619-20); Las Encinas (Van Denburgh, 1922); Matomi (FMNH 1059[3]); Nochoguero Valley (Van Denburgh, 1922); Ojos Negros (USNM 37675-6) ; Palo Gacho (LMK 10369) ; Parral (FMNH 1060[3]); Pt. San Antonito, San Nicolas Bay (CAS 53600); Rosarito (FMNH 1554); San Antonio (FMNH 1061[5]; LMK 8823-9); San Antonio Ranch (MVZ 9741; USNM 37665) ; San Antonio de Sarravia (LMK 5121-3); San Francisco Island (CAS 52704-6; LMK 4042); San Ignacio (UMMZ 76482-3[3]; MVZ 10653-4, 10656, 13599, 13597; LMK 4053-4) ; San Jose", San Pedro Martir Mts. (CAS 57396- 412, 65778-80; LMK 4691-4, 5124-5); San Marcos Island (CAS 51593-6); San Pedro Martir Mts. (LSJU 700-1; USNM 23716-7); San Pedro (LMK 10371); San Rafael Valley (LSJU 704); San Salado River Canyon (FMNH 1063[2]); Santa Rosalia (Mocquard, 1899); San Telmo River (LMK 4041); 2 mi. N of San Vicente Ranch (CAS 57600); San Xavier (Van Denburgh, 1922); Socorro Mine (LMK 10526); Tortuga Island (CAS 51356-459; LMK 4047-9, 6844-5); Trinidad (FMNH 1064); Valladares (MVZ 9733-4); Valle Trinidad (SDSNH 16865-8); Wasson's Ranch, San Rafael Valley (LSJU 702-3); Zacatosa (LMK 10370). Sceloporus orcutti licki Van Denburgh. Sceloporus licki Van Denburgh, Proc. Calif. Acad. Sci., (2), 5, pp. 79, 110-114, pi. 10, 1895; Boulenger, Proc. Zool. Soc. Lond., 1897, pp. 500-501, 1897; idem, 1898, p. 915, 1898; Mocquard, Nouv. Arch. Mus. Hist. Nat. Paris, (4), 1, p. 313, 1899; Cope, Ann. Kept. U. S. Nat. Mus., 1898, p. 363, 1900; Stejneger and Barbour, Check List N. Amer. Amph. Kept., p. 54, 1917; Nelson, Mem. Nat. Acad. Sci., 16, pp. 114, 115, 1922; Schmidt, Bull. Amer. Mus. Nat. Hist., 46, p. 663, 1922; Van Denburgh, Occ. Papers Calif. Acad. 1 McLain (1899a) reports o. orcutti from White River, Tulare County, a record undoubtedly incorrect. 1939 MEXICAN LIZARDS SMITH 141 ScL, 10, pp. 356-358, 1922; Stejneger and Barbour, Check List N. Amer. Amph. Kept., 2nd ed., p. 56, 1923; Linsdale, Univ. Calif. Publ., Zool., 38, p. 367, 1932; Stejneger and Barbour, Check List N. Amer. Amph. Kept., 3rded., p. 62, 1933; Ditmars, Kept. N. Amer., p. 59, 1936. Type locality. Sierra San Lazaro, Lower California. Neotype 1 LSJU 2987a (one of two paratypes), collected by Eisen and Vaslit. Distribution. Cape region of Lower California, including Isla Espiritu Santo and Isla Partida (fig. 12). Diagnosis. A relatively small species of the spinosus group, maximum snout-vent measurement 94 mm.; dorsal scales 32 to 40, average 36; ventral scales 35 to 52, average 42.5; scales around body 31 to 42, average 36; femoral pores 13 to 19, average 15.8; five supraoculars, the two posterior in contact with median head scales; first canthal in contact with lorilabials; gular region barred; a black shoulder patch, with a light posterior border; outer row of labio- mentals separated from mental; lorilabials usually reduced below subocular by one or more scales in contact with both subocular and supralabials. Description. 2 Dorsal head scales smooth, pitted; two parietals, the posterior narrow, transverse, the anterior over twice as large, sub triangular; interparietal pentagonal, slightly more than twice size of anterior parietal; frontoparietal single, twice as long as broad; frontal in contact with interparietal; frontal normally divided; five supraoculars, the fourth and fifth entirely in contact with median head scales; row of scales between supraoculars and superciliaries terminating at suture between third and fourth supraoculars; one complete and another incomplete row of small scales between all supraoculars (except first) and superciliaries; six superciliaries, five visible from above; pref rentals in contact medially; frontonasals normal; two pairs of internasals; four postrostrals, separating nasals and internasals from rostral; subnasal present on one side; two canthals, the first in contact with lorilabials; one loreal; preocular entire; lorilabials reduced to one row below subocular by a scale in contact with both subocular and infralabials; two postoculars; two complete rows of lorilabials in labial region; four or five supra- labials and five or five and one-half infralabials to a point below middle of eye. 1 The type and all of the paratype series in the California Academy of Science were destroyed by the fire of 1906. Two paratypes are preserved in Stanford University. 2 Based on UMMZ 56044, male, San Bartolo, Lower California. 142 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 Mental pentagonal, with a labial border slightly more than half that of rostral; four or five pairs of postmen tals, the scales of the anterior pair in contact medially, the others separated; outer row of labiomentals narrowly separated from mental by partial contact of first infralabial and first postmental; all gular scales except those in extreme anterior part, just behind the postmentals, with a single apical notch; median and posterior gular scales somewhat smaller than lateral gular scales. Auricular lobules six, the median scales the largest, extending across ear; lobules pointed, smooth, larger than preceding scales; temporal scales weakly keeled, weakly mucronate and denticulate, the anterior scales smaller than posterior scales, the largest smaller than median scales between ear and lateral nuchal pocket; scales in latter region strongly keeled, strongly mucronate, strongly denticu- late, subequal in size to scales between arm and nuchal pocket; lower scales in latter region very weakly keeled, weakly mucronate, weakly denticulate, directed posteriorly; upper scales in this region more strongly keeled and mucronate, the keels directed upward and caudad. Dorsal scales keeled, strongly mucronate, denticulate, in parallel rows; lateral scales similar to dorsal scales, more strongly denticulate, about two-thirds size of dorsal scales; ventral scales notched, smooth, those on chest somewhat larger than those on abdomen; preanal scales notched, subequal in size to abdominal scales. Dorsal scales of foreleg strongly keeled, strongly mucronate, denticulate, subequal in size, about one-third size of dorsal body scales; ventral scales of lower foreleg about three-fifths size of dorsals of same member, the posteroventral scales keeled, the anterior and anteroventral scales smooth, notched; scales in axilla granular; ventral scales of upper foreleg smooth, notched, about two-thirds size of ventral scales of lower foreleg; lamellar formula for fingers 10-14-18-19-14 (9-13-17-18-13). Dorsal scales of hind leg keeled, strongly mucronate, denticulate, those on shank somewhat larger than those on thigh and about two- thirds size of dorsals on body; scales on anterior and ventral surfaces of thigh smooth, notched, becoming smaller toward femoral pore series; scales on posterior surface of thigh keeled, mucronate, denticu- late, largest medially, the largest scales subequal in size to preanal scales; ventral scales of shank smooth, notched, subequal in size to dorsal scales of same member; lamellar formula for toes 10-14- 18-23-16 (10-14-18-23-16). 1939 MEXICAN LIZARDS SMITH 143 Dorsal caudal scales somewhat larger than dorsals on body, keeled, strongly mucronate, denticulate; subcaudals smooth, notched; enlarged postanals present in males; no postfemoral dermal pocket. Color. Adult males are dark reddish brown above; a broad median area on the back is immaculate; most of the scales on the sides of the body with one or more indefinitely outlined pale blue spots; limbs with fairly distinct alternating dark and light bands; distal part of tail faintly banded; labia very distinctly barred, the most conspicuous dark band passing through middle of eye; a black shoulder spot, bordered posteriorly by a light line extending across anterior margin of arm insertion; a light pineal spot; sometimes a light bar across prefrontals and a light median spot on each parietal and frontoparietal. Ventral surfaces of arms, and chest near arm insertion, white; gular fold region and anterior part of chest black, the color continuous with the black shoulder patch; most of throat black or dark blue, sometimes with a lighter blue central area; chin and part of infralabial region white; lower labia barred, the bars sometimes visible in the central part of the gular region; a broad black streak down middle of abdomen, confluent over chest with black gular fold area; abdo- men lateral to this median streak dark blue, becoming lavender toward sides of body, some of the scales frequently with pale blue centers; interfemoral region, anterior part of preanal region, groin, and most of the ventral surfaces of the thighs dark blue or black; ventral surfaces of tail and shank white or cream color. Young males are similar, but have a dorsolateral light line extending from the posterior corner of the eye to the base of the tail, becoming quite indistinct posteriorly; below this line on the sides of the body is a brown band, narrow anteriorly, extending from the lower posterior margin of the eye to the groin; this lateral brown stripe merges insensibly on the sides of the body with the color of the ventral surface; the light lateral stripe becomes indistinct with increase in size; in the smallest specimens there is a narrow dark line above the dorsolateral light line, and another down the middle of the back; these three dark stripes are separated from each other by two lighter stripes of subequal width; all these stripes indistinct posteriorly; sometimes the three dark dorsal stripes are broken into irregular series of small spots. The black shoulder patch is distinct in the young. The ventral surfaces are colored much as in the adult males, except much less intensely; the youngest have the abdomen immaculate; the groin and the dark medial border of the lateral 144 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 abdominal patches are the first to become differentiated with increasing age; the throat is blue-gray in all, with usually rather narrow, convergent white bands. Females are similar to young males in dorsal coloration. The dorsolateral light stripe is perhaps more distinct. The throat is barred. Variation. The variation in cephalic scutellation of 40 speci- mens is as follows: parietals two in all; frontoparietals divided on one side in two; frontal touches interparietal in all; anterior section of frontal longitudinally divided in one; five superciliaries in one; supraoculars five to seven (5, fifty-seven; 6, twenty- two; 7, one); prefrontals in contact in all; one pair of internasals in 37, two pairs in three; subnasal absent on both sides in 22, on one side in nine; first canthal in contact with lorilabials in 39; preocular divided on one side in three, on both sides in 14; three postrostrals in three, four in others; two complete rows of lorilabials below subocular on one side in two, on both sides in four. Dorsal scales 32 to 40, average 36 (34 counts: 32, two; 33, three; 34, four; 35, six; 36, eight; 37, eight; 39, two; 40, one); ventral scales 35 to 52, average 42.5 (40 counts: 35, one; 37, one; 38, two; 39, five; 40, six; 41, three; 42, five; 43, four; 44, two; 45, two; 46, two; 47, two; 49, three; 50, one; 52, one); scales around body 31 to 42, average 36 (40 counts: 31, one; 32, one; 33, three; 34, five; 35, seven; 36, six; 37, eight; 38, four; 39, two; 40, two; 42, one). Femoral pores 13 to 19, average 15.8 (78 counts: 13, two; 14, nine; 15, twenty-two; 16, twenty-four; 17, sixteen; 18, four; 19, one). Comparisons. Sceloporus o. licki differs from o. orcutti, its closest relative, in smaller maximum size; in average body scale counts; in average number of femoral pores; in having the lorilabial scale rows reduced below subocular; in having a distinct, black shoulder patch, with a light posterior border in both sexes; in the absence of a light spot in the center of the dorsal scales; by the presence, in females and young males, of a dorsolateral light line, rather distinct anteriorly, indistinct posteriorly; in the absence of a barred pattern in females. So far as known at present, the ranges of o. licki and o. orcutti are not contiguous, although they closely approach each other (about 30 miles). It appears quite likely that future collecting will demonstrate complete intergradation in the small area from which no specimens are known at present. In the absence of definite characters separating the two forms, and because of the probable 1939 MEXICAN LIZARDS SMITH 145 intergradation in southern Lower California, the two are here con- sidered subspecies. Locality records. LOWER CALIFORNIA. Agua Caliente (CAS 46790-1; MVZ 11709-11); Ballena Island (CAS 52866-79) ; Cabo San Lucas (CAS 46800-8; AMNH 5437; MCZ 1); Corral de Piedras (Van Denburgh, 1922); El Sauz (MVZ 11702-8); Espiritu Santo Island (LMK 4050-2, 7252-3; AMNH 5485-6; USNM 37670); Guamuchil Rancho (CAS 46809); Isla Partida (CAS 52782-812, 52829-30; LMK 6850-6, 7254-5; FMNH 18413); La Paz (CAS 46775; USNM 53392); Miraflores (AMNH 5564, 5702; USNM 64472; USNM 23749); San Antonio (CAS 46830); San Bartolo (CAS 46780-7; UMMZ 56044); San Bernardo Mt. (AMNH 5487); Sierra El Taste (Van Denburgh, 1922); Sierra San Lazaro (LSJU 2987-8); Todos Santos (CAS 46810-2, 46815-24; MVZ 11701; AMNH 20505); Triunfo (CAS 46779, 46825-8). Sceloporus magister magister Hallowell. Sceloporus clarkii Baird and Girard, Proc. Acad. Nat. Sci. Phila., 6, p. 127, 1852 (part); Yarrow & Henshaw, in Wheeler, Ann. Kept. Geog. Surv. West 100th Mer., 1878, p. 223, 1878 (part); Stejneger, N. Amer. Fauna, 3, pp. 110-111, 1890 (part); Cope, Amer. Nat., 30, p. 1014, 1896 (part); idem, Ann. Kept. U. S. Nat. Mus., 1898, pp. 358-363, 1900 (part); Stone and Rehn, Proc. Acad. Nat. Sci. Phila., 55, pp. 30, 31, 1903 (part) ; Bailey, N. Amer. Fauna, 25, p. 42, 1905; Mearns, Bull. U. S. Nat. Mus., 56, pt. 1, pp. 104, 107, 110, 123, 126, 132, 1907 (part ?); Ditmars, Kept. Book, pp. 128, 131-133, 1907 (part); idem, Kept. World, p. 147, 1910 (part); idem, Kept. World, revised ed., p. 147, 1922 (part); Englehardt, Copeia, 1917, p. 5, 1917; Burt, Trans. Kans. Acad. Sci., 38, pp. 275, 299, 305, 1936 (part). Sceloporus magister Hallowell, Proc. Acad. Nat. Sci. Phila., 7, p. 93, 1854; Dumeril, Arch. Mus. Hist. Nat. Paris, 8, p. 547, 1856; Hallowell, U. S. Pacif. R. R. Explor. Surv., 10, Lieut. Williamson's Rept., p. 5, 1859; Heer- man, U. S. Pacif. R. R. Explor. Surv., 10, Lieut. Williamson's Rept., p. 24, 1859; Troschel, Arch. Naturg., 26, pt. 2, p. 272, 1860; Mttller, Reisen Ver. Staaten, Canada, Mex., 3, p. 602, 1865; Cooper, Proc. Calif. Acad. Sci., 4, p. 66, 1870; idem, Amer. Nat., 3, p. 478, 1870; Duges, Naturaleza, 4, p. 30, 1877; Stejneger, N. Amer. Fauna, 7, pp. 160, 178-183, pi. 1, figs. 2 a-c, 1893; Van Denburgh, Proc. Calif. Acad. Sci., (2), 5, pp. 82, 113, 1895; Cockerell, Amer. Nat., 30, p. 326, 1896; Van Denburgh, Proc. Calif. Acad. Sci., (2), 6, pp. 340, 341, 1896; idem, Occ. Papers Calif. Acad. Sci., 5, pp. 13, 14, 20, 74, 83, 84-86, 1897; Herrick, Terry and Herrick, Bull. Sci. Lab. Denison Univ., 11, pp. 125-126, pi. 16, figs. 9-11, 1899; McLain, Collec. Rept. West- ern Coast U. S., p. 8, 1899 (part); Stejneger, Proc. U. S. Nat. Mus., 25, p. 150, 1902; Meek, Field Mus. Nat. Hist., Zool. Ser., 7, p. 10, 1905; Grinnell and Grinnell, Throop Inst. Bull., 35, pp. 55-56, fig. 21, 1907; Ruthven, Bull. Amer. Mus. Nat. Hist., 23, pp. 532-536, 537, 538, 1907; Grinnell, Univ. Calif. Publ., Zool., 5, p. 162, 1908; Stone, Proc. Acad. Nat. Sci. Phila., 146 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 63, p. 227, 1911; Van Denburgh, Proc. Calif. Acad. Sci., (4), 3, p. 148, 1912; Atsatt, Univ. Calif. Publ., Zool., 12, pp. 37, 46, 47, 48, 1913; Bailey, N. Amer. Fauna, 35, p. 20, 1913; Van Denburgh and Slevin, Proc. Calif. Acad. Sci., (4), 3, pp. 392, 404-405, 1913; Richardson, Proc. U. S. Nat. Mus., 48, pp. 403, 404, 405, 418-419, 1915; Van Denburgh and Slevin, Proc. Calif. Acad. Sci., (4), 5, p. 100, 1915; Camp, Univ. Calif. Publ., Zool., 12, pp. 507, 526-527, 1916; Grinnell and Camp, Univ. Calif. Publ., Zool., 17, pp. 162-163, 1917; Riithling, Lorquinia, 2, pp. 9-11, 1917; Stejneger and Barbour, Check List N. Amer. Amph., p. 55, 1917; Dickerson, Bull. Amer. Mus. Nat. Hist., 41, p. 468, 1919; Hall and Grinnell, Proc. Calif. Acad. Sci., (4), 9, p. 48, 1919; Cowles, Jour. Ent. Zool., 12, p. 65, 1920; Stephens, Trans. San Diego Soc. Nat. Hist., 3, p. 62, 1921; Van Denburgh and Slevin, Proc. Calif. Acad. Sci., (4), 11, pp. 28, 34, 1921; Bequaert, Bull. Amer. Mus. Nat. Hist., 45, p. 296, 1922; Schmidt, Bull. Amer. Mus. Nat. Hist., 46, pp. 661, 663, 1922; Van Denburgh, Occ. Papers Calif. Acad. Sci., 10, pp. 329-338, pi. 27, 1922; Camp, Bull. Amer. Mus. Nat. Hist., 48, pp. 378, 400, 1923; Stejneger and Barbour, Check List N. Amer. Amph. Kept., 2nd ed., p. 57, 1923; Van Denburgh, Proc. Calif. Acad. Sci., (4), 13, pp. 191, 206, 1924; Ortenburger and Ortenburger, Proc. Okla. Acad. Sci., 6, p. 107, 1926; Ruthven, Occ. Papers Mus. Zool. Univ. Mich., 179, pp. 1-2, 1926; Tanner, Copeia, 1927, p. 56, 1927; Klauber, Zool. Soc. San Diego, Bull., 4, p. 3, 1928; Springer, Copeia, 1928, pp. 100, 102, 104, 1929; Woodbury, Copeia, 1928, p. 17, 1928; Burt and Burt, Jour. Wash. Acad. Sci. 19, p. 451, 1929; Bogert, Bull. S. Calif. Acad. Sci., 19, p. 7, 1930; Klauber, Zool. Soc. San Diego, Bull. 5, p. 3, 1930; idem, 8, pp. 47, 80, 1931 ; Woodbury, Bull. Univ. Utah., 21, No. 5, pp. 9, 13, 37, 43-44, 1931; Barry, Copeia, 1932, p. 103, 1932; Klauber, Copeia, 1932, p. 122, 1932; Ruthven, Occ. Papers Mus. Zool. Univ. Mich., 243, p. 3, 1932; Barry, Copeia, 1933, p. 100, 1933; Stejneger and Barbour, Check List N. Amer. Amph. Rept., 3rd ed., p. 62, 1933; Woodbury, Ecol. Monog., 3, p. 194, 1933; Knowlton, Jour. Econ. Ent., 27, p. 1002, 1934; Knowlton and Thomas, Proc. Utah Acad. Sci., 11, p. 258, 1934; McKee and Bogert, Copeia, 1934, p. 179, 1935; Slevin, Handb. Rept. Amph. Pacif. States, pp. 43, 52, 58, 63, 69, 1934; Tan- ner and Hayward, Proc. Utah Acad. Sci., 11, p. 224, 1934; Burt, Trans. Amer. Micr. Soc., 54, p. 171, 1935; idem, Trans. Kans. Acad. Sci., 38, p. 275, 1936; Eaton, Copeia, 1935, p. 151, 1935; idem, Rainbow Bridge Mon. Valley Exped., Bull. 3, pp. 15-16, 1935; Tanner, Proc. Utah Acad. Sci., 12, p. 268, 1935; Wood, Jour. Parasit., 21, pp. 166, 167, 168, 173, 1935; Ditmars, Rept. N. Amer., pp. 47, 51, 1936; Gloyd, Program Activ. Chicago Acad. Sci., 8, p. 16, 1937. Sceloporus spinosus Yarrow, U. S. Geog. Surv. W. 100th Mer., 5, pp. 574-575, 1875 (?part); Coues, U. S. Geog. Surv. W. 100th Mer., 5, p. 588, 1875 (?part); Yarrow, Bull. U. S. Nat. Mus., 24, p. 63, 1883 (?part); idem, Smithson. Misc. Collec., 517, p. 10, 1883 (?part); Giinther, Biol. Cent.- Amer., Rept. Batr., p. 63, 1890 (part). Sceloporus clarkii clarkii Cope, Bull. U. S. Nat. Mus., 1, pp. 49, 92, 1875 (part); Yarrow, U. S. Geog. Surv. W. 100th Mer., 5, pp. 575-576, 1875 (part); Burt, Trans. Kans. Acad. Sci., 38, pp. 275, 299, 305, 1936 (part); Burt, Papers Mich. Acad. Sci., 22, pp. 533, 534, 1937. 1939 MEXICAN LIZARDS SMITH 147 Sceloporus clarki clarki Coues, U. S. Geog. Surv. W. 100th Mer., 5, p. 594, 1875 (part); Yarrow, Bull. U. S. Nat. Mus., 24, p. 63, 1883 (part); idem, Smithson. Misc. Collec., 517, p. 11, 1883 (part). Sceloporus spinosus clarkii Boulenger, Cat. Liz. Brit. Mus., 2, p. 277, 1885 (part); idem, Cat. Liz. Brit. Mus., 3, p. 503, 1887 (part); Brown, Proc. Acad. Nat. Sci. Phila., 55, pp. 546, 552, 556, 1903 (part); Strecker, Baylor Bull., 18, No. 4, p. 20, 1915. Sceloporus spinosus magister Boulenger, Proc. Zool. Soc. Lond., 1897, pp. 492, 496, 1897 (part). Sceloporus zosteromus Meek, Field Mus. Nat. Hist., Zool. Ser., 7, p. 11, 1905 (part). Sceloporus magister magister Linsdale, Univ. Calif. Publ., Zool., 38, p. 365, 1932; Burt, Amer. Mid. Nat., 14, pp. 237-238, 1933; Klauber, Zool. Soc. San Diego, Bull., 11, pp. 11-12, 1934; Cowles and Bogert, Herpetologica, 1, p. 38, 1936; Gloyd, Bull. Chicago Acad. Sci., 5, pp. 98, 100, 112, 1937; Taylor, Univ. Kans. Sci. Bull., 24, pp. 477, 484, 1938. History. Stejneger's excellent summary of the history of m. magister (1893, pp. 178-179) can scarcely be improved upon. Subsequent to 1893, two monographic studies of the genus have appeared. Boulenger (1897) considered magister and floridanus con- specific, but conceded them subspecific rank under spinosus. S. clarkii was also considered a subspecies of spinosus. Cope (1900) disagreed with Stejneger and regarded magister as a synonym of clarkii. Most authors who have dealt with the species since 1900 have recognized the validity of Stejneger's conclusions. The most notable exception is Burt (1935 and 1936), who concludes that the two species are identical. Linsdale (1932) is apparently the first to recognize subspeciation in magister. There is little wonder that difficulty should have arisen in the separation of magister and clarkii, in view of the nature of the types. The type of magister has, thanks to Stejneger's careful study, been correctly defined; however, the three cotypes of clarkii include two species: two are specimens of magister and the other is typical of the species Stejneger defined as clarkii. This latter specimen has a white tag on its leg, and has been designated above as the lectotype of clarkii. Type locality. Fort Yuma, California. Distribution. Southern California, excluding the western slopes, northeastern Lower California, Arizona, New Mexico, southern Nevada and Utah, southwestern Colorado, extreme western Texas, and southward to northern Durango and southern Sonora (fig. 13). Diagnosis. A large Sceloporus of the spinosus group, maximum snout-vent measurement 140 mm.; dorsal scales 26 to 37, average 148 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 32.2; ventral scales 40 to 51, average 44.3; scales around body 32 to 39, average 35.5; femoral pores 10 to 16, average 12.8; dorsal scales mucronate, keeled; some of upper lateral scales somewhat larger than median dorsal scales; two parietals on each side; usually five supraoculars on each side, the two posterior usually in contact with median head scales (rarely only the posterior); first canthal usually in contact with lorilabials; outer row of labiomentals in contact FIG. 13. Distribution of the subspecies of Sceloporus magister in Mexico: S. m. magister, Q; S. m. rufidorsum, A; S. m. monserratensis, Q; S. m. lineatulus, O; and S. TO. zosteromus, V. with mental; auricular lobules four to eight, elongate, pointed, the median lobules somewhat larger than upper lobules. Lateral scales not dark-sided; females and young with two series of small, dark spots on back; a black or dark gray band on neck (absent, except on shoulder, in adult males); bars, when present on back, distinct and narrow; limbs not distinctly barred; tail usually distinctly banded. Description. 1 Head scales smooth, pitted, somewhat convex; interparietal sub triangular; parietals double on either side, the anterior about two-thirds size of interparietal, the posterior narrow, 1 Based on a female, EHT collection, sandhills north of El Paso, Texas. 1939 MEXICAN LIZARDS SMITH 149 smaller; frontoparietals single on each side, sub triangular, narrowed anteriorly, slightly more than half size of either parietal; frontal in contact with interparietal ; posterior section of frontal somewhat smaller than anterior section; two pref rentals, broadly in contact medially, about the size of posterior section of frontal ; three fronto- nasals, subequal in size; a small scale wedged between median and lateral frontonasals on each side at their anterior borders; internasals quite irregular; supraoculars five, the anterior smallest and in contact with first superciliary, the others approximately equal in size; a series of small scales intercalated between supraoculars and median head scales, beginning anteriorly at second canthal, terminating posteriorly near the suture between the fourth and fifth supraoculars; a small scale intercalated between fifth supraocular and parietal at their posterolateral margins; a single series of small scales inter- calated between supraoculars and superciliaries, extending from posterior edge of first supraocular to posterior edge of last supra- ocular; five superciliaries visible from above; two canthals, the first touching the lorilabials; subnasal quite small; nasal touching lori- labials immediately in front of subnasal; preocular not divided; a small scale intercalated between preocular and subocular at lower margin; subocular rather long, followed posteriorly by two keeled, well-differentiated postoculars; approximately four supralabials and five infralabials to a point below middle of eye. Mental broadly shield-shaped, with a labial border slightly more than half that of rostral; outer row of labiomentals in contact an- teriorly with mental; about three pairs of well-differentiated post- mentals, the scales of the anterior pair in contact with each other medially, the others separated; inner row of labiomentals extending anteriorly to a point below posterior part of second infralabial; gular scales smooth, most with a single apical notch, smaller anter- iorly and toward sides of head; scales below ear weakly keeled; scales in gular fold region with not more than two apical notches. Auricular lobules four-five, the median scales larger than others and extending completely across tympanum; all auricular lobules smooth, acuminate, or rounded, considerably smaller than preceding scales; temporal scales weakly keeled, mucronate toward ear, notched toward eye, smaller than largest scales between ear and lateral nuchal pocket; latter surmounted by weakly keeled, strongly mucronate, denticulate scales; scales between lateral nuchal fold and arm sub- equal in size to largest temporal scales, very weakly keeled, mucro- nate, with a single notch on either side of terminal mucrone. 150 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 Dorsal scales rather weakly keeled, strongly mucronate, with several lateral mucrones; median lateral scales somewhat smaller than median dorsal scales, of the same character as the latter; ventral abdominal scales with one or two apical notches, one-half to two-thirds size of median dorsal scales; preanal scales one-third or one-fourth smaller than scales in interfemoral and ventral ab- dominal regions. Dorsal scales of foreleg much smaller than median dorsals on body (about half), keeled, mucronate, denticulate, somewhat smaller on lower foreleg than on upper foreleg; scales on ventral surface of lower foreleg somewhat smaller than dorsal scales of same member, much larger than ventral scales on upper foreleg, smooth and notched posteriorly, keeled, mucronate and denticulate anteriorly and toward hand; lamellar formula for fingers 8-12-16-15-10 (7-12-16-16-11). Dorsal scales of hind leg keeled, mucronate, denticulate, subequal in size, or those on shank somewhat larger than those on thigh, the largest but little larger than dorsals on foreleg; ventral scales of shank subequal in size to dorsal scales of same member, smooth, with two apical notches; scales on anterior surface of thigh smooth, acuminate, notched, becoming smaller ventrally toward femoral pore series; scales in a median area on posterior surface of thigh keeled, mucronate, denticulate, somewhat larger than preanal scales, much larger than adjacent scales toward tail, shank, and femoral pores, continuous with larger dorsal scales of thigh; no postfemoral dermal pocket; lamellar formula for toes 8-11-16-20-14 (8-11-16- 20-13). Dorsal scales on rump somewhat reduced in size; dorsal caudal scales nearly as large at base of tail as median dorsal scales on body, much reduced in size distally, strongly keeled, strongly mucronate, strongly denticulate; subcaudals smooth proximally, keeled distally. Color. Ruthven (1907, pp. 533-534) describes the color, appar- ently in life, as follows: "The color is variable, and the pattern not well defined. The head above is usually mottled with dark brown and yellow or light brown. A narrow brown line extends along the infraorbital scutes from the canthus rostralis, and is continuous on the neck to the shoulder. A similar line parallel to this one extends from the supra- labials also to the shoulder. On the nape there are usually indications of narrow V-shaped bands. These are rarely distinct with the excep- tion of the posterior one, which forms a narrow black collar that usually terminates on the side of the neck. 1939 MEXICAN LIZARDS SMITH 151 "On either side of the back, about five rows of scales apart and two rows wide, are two longitudinal light bands that are usually some shade of yellow, and may be either quite distinct or obscure. On either side of each light stripe is a row of indefinite dark brown or black spots, the middle two of which may unite to form transverse bands across the back. The scales not included in the stripes are usually yellow and brown, but there are often on the back and sides many blue scales, and these may be numerous enough to form blotches or a solid, broad blue band between the stripes, and to give a bluish cast to the side. This tendency is most conspicuous in male specimens. Again all or most of the scales on the back, sides, and neck may be margined with orange or red, giving an orange appear- ance to the body. The tail is usually rather distinctly banded above with light brown, and dark brown or black. The scales on the limbs are mostly yellow with brown lateral margins which connect with those of adjacent scales, giving the appearance of narrow longi- tudinal stripes. "In old males the pattern above may be nearly obsolete, and the color very dark, the scales being blue black and dark brown. When the skin is shed the color is uniformly yellowish. "The under surface in females and young specimens is usually light yellow. In the males there is generally a narrow central band of white or yellow but on either side of this are two large blotches of bright metallic blue, occasionally with interspersed scales of bright yellow. The individual scales in the blue area are generally narrowly margined with black. Tail and ventral surface of limbs bluish white. A bright blue spot on the gular region, that may extend over the entire throat, but usually becomes lighter on the anterior part. In nearly all the specimens the black collar is continued across the throat by black edgings to the scales." Specimens from the northern part of the range more frequently show a development of transverse dark bars on the back, although similarly marked specimens occur in all parts of the range. Camp (1916) gives the following notes on specimens from the Turtle Mountain region, southeastern California: "The coloration of the adult males varies a good deal, and this variation is especially noticeable in the vivid ventral colors. One male has the neck band pure black, the throat patch Olympic blue of the sheen of porcelain, the darkest belly scales urania blue of a porcelain cast, the scales laterally on the ventral patch variscite green to Blanc's blue. Many of the scales along the sides of the body 152 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 are edged with rufous and have brown centers. Scales on the sides of the tail are opaline green. The general color of the upper parts and the top of the head is deep olive buff to buffy brown. . . . "The ventral patches are in three specimens divided and in one united. There are no indications of dorsal cross bands or spotting in any of the males. The female is marked dorsally with sixteen brown patches, about a scale in width. The lower surface is creamy white lightly tinted on scattered scales with pale greenish, pale orange and, beneath the throat, pale blue. The collar of the female is brown." Variation. The following variation in head scutellation is recorded from 113 specimens, unless otherwise stated. Two parietals on each side in all; two frontoparietals on one side in one, on both sides in two; frontal contacts interparietal in 86; frontoparietals contact medially in 17, separated by an azygous scale in eight; frontal entire in two; posterior section of frontal transversely divided in two; anterior section of frontal divided into three scales in one, longitudinally in nine; superciliaries five to seven (162 counts: 5, seventeen; 6, one hundred and forty; 7, five); supraoculars four to seven (226 counts: 4, four; 5, two hundred and three; 6, eighteen; 7, one); only posterior supraocular in contact with median head scales in five counts, two posterior supraoculars in contact in 151 counts, three posterior supraoculars in contact with median head scales in six (81 specimens, 162 counts) ; prefrontals contact medially in 102, separated by an azygous scale -in eight; frontal narrowly in contact with median frontonasal in three; median frontonasal separated from lateral frontonasals on both sides in one, on one side in six, otherwise frontonasals normal; two typical pairs of internasals in 61 (81 counts), three pairs in three, one pair followed by three scales in eight, one pair in three, two pairs followed by three scales in one, irregular in five; nasal contacts rostral in none; subnasal absent (fused with first canthal) on one side in four, on both sides in two (81 specimens); first canthal in contact with lorilabials on one side in six, on neither side in eight, on both sides in 99; preocular divided on one side in eight, on both sides in 17, on neither side in 88; loreals none to two (162 counts: none, three [fused with first canthal]; 1, one hundred and fifty-six; 2, three); four postrostrals in all (81 counts) ; two complete rows of lorilabials below subocular on one side in five, on both sides in 98, on neither side in 10 (reduced to one row at some point below subocular by one or more scales in contact with both subocular and supralabials) ; outer row of labio- 1939 MEXICAN LIZARDS SMITH 153 mentals contacts mental in all; inner row of labiomentals terminating anteriorly between a point even with anterior part of third infralabial and a point even with posterior part of first infralabial. Dorsal scales 26 to 37, average 32.2 (90 counts: 26, one; 28, two; 29, six; 30, nine; 31, ten; 32, seventeen; 33, twenty-five; 34, thirteen; 35, three; 36, three; 37, one); ventral scales 40 to 51, average 44.3 (91 counts: 40, two; 42, twelve; 43, nineteen; 44, nine- teen; 45, eighteen; 46, fourteen; 47, four; 48, two; 51, one); scales around body 32 to 39, average 35.5 (91 counts: 32, two; 33, three; 34, sixteen; 35, twenty-nine; 36, twenty-one; 37, twelve; 38, six; 39, two). Femoral pores 10 to 16, average 12.8 (173 counts: 10, five; 11, sixteen; 12, fifty-one; 13, fifty-four; 14, forty; 15, six; 16, one). There is no geographical correlation in the above variational data. Extremes or near-extremes are found in all parts of the range of magister magister. Specimens from Nevada and the Grand Canyon region appear different, but I can find no constant differences, either in coloration or scutellation, which might define other races. Habits and habitat. Apparently there is some variation in habitat preference in various parts of the range of m. magister. , Tree yuccas, catclaw thickets, piles of rocks, undercut wash-banks, railroad culverts, ruins of stone or adobe dwellings, and wood-rat nests are frequented. "At the mouth of Beaverdam Creek in northwestern Arizona it was common among cottonwood logs and dead leaves; in Pahranagat Valley it was abundant about the ruins of stone houses and along the faces of cliffs; in the Mohave Desert and other localities it is common on the tree yuccas, where it was often found on the very summits of the highest branches . . . ." (Merriam in Stejneger, 1893.) A specimen collected in Durango was near the top of a telephone pole, and others were seen on other poles. Ruthven (1907) states that "the few specimens found at Alamo- gordo were all taken in the creosote bush association on the alluvial slope. They climb about in these bushes much as they do in the large Opuntias about Tucson. . . . "Tucson. The habitat of S. magister is well defined in this region. It is quite common on the greasewood plains, but seems to be excluded from the flood-plains of the larger streams (mesquite and willow- poplar associations). Mr. Jouy appears to have been the first to observe that its habitat thus differs from that of S. clarkii. Although it occurs in the suaharo-ocotillo association at the foot of the Santa Catalina and Tucson Mountains, it is much less common in these 154 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 places. Its principal habitat in this region is thus pre-eminently the creosote bush association of the plains. "It is very wary and rather difficult to secure as it does not run about on the desert as do the Crotaphyti and Cnemidophori but resides in the bushes. Individuals were occasionally observed in mesquite or creosote bushes, and more often beneath the Crucifixion thorn, but it evidently prefers the tall branching Opuntias, especially the larger ones. Here it may be seen very commonly on the trunks, upon the highest branches or in the nests of wood rats which are constructed of the detached branches of these shrubs on the ground beneath. If the bushes are approached at a good pace the chances are that no lizards will be seen, for when frightened they scramble swiftly down the stems and into a hole, if there is time, or if not flatten themselves out against the trunk of the shrub or among the dead branches on the ground. In such cases they do not give them- selves away by the teetering movement so characteristic of many lizards, and their extraordinary resemblance to the trunk or a lobe of an Opuntia makes them very difficult to discern. Many times I have seen an individual scuttle down the trunk of one of these cacti but on carefully approaching the bush would be unable to distinguish it, although it would be in full view. ..." Richardson (1915) found specimens at Wadsworth, Nevada, in bushes near the river. At Pyramid Lake, Nevada, they were also in bushes near the river, "on tufa cliffs near the lake, or on volcanic rocks in the nearby hills, also along the lake shore, but never very far out on the desert." Richardson says (1915), that when the specimens are running from bush to bush, the tail is lifted above the level of the body in much the same manner as in Callisaurus. Linsdale (1932) reports one found asleep in early morning on the main limb of a small mesquite tree. The food consists of insects and some vegetation. Merriam (in Stejneger, 1893), Camp (1916), Knowlton (1934), and Knowlton and Thomas (1934) record plant remains in stomachs examined, including fruit, leaves, and flowers. Dr. Edward H. Taylor states that he has observed specimens feeding upon flowers of cacti. Insect food has been recorded by several authors. Ants seem to predominate, and Coleoptera seem to be second in preference. Stinging insects, such as velvet ants and bees, are not avoided. The food naturally varies somewhat with the habitat. Coleoptera, according to Eaton (1935), predominate in stomachs of specimens from localities near Agathla Peak, near Kayenta, Navajo County, Arizona. The locality here 1939 MEXICAN LIZARDS SMITH 155 "is rough ground, cut by arroyos and covered with ledges and a scattering of scrubby pine trees, among which the lizards lived. They were usually near the base of a tree. . . ." Families or orders of insects recorded in stomach contents are as follows: Orthoptera, Homoptera, Fulgoridae, Hemiptera, Neuroptera, Chrysomelidae, Buprestidae, Coccinellidae, Tenebrionidae, Carabidae, Dermestidae, Curculionidae, Diptera, Ichneumonidae, Vespidae, Mutillidae, Api- dae, Andrenidae, Formicidae, and Lepidoptera (adults and larvae). Spiders have been recorded. Woodbury (1934) records a Cnemidophorus t. tessellatus in the stomach of one specimen. Riithling (1917) observed specimens in captivity eating Xantusia vigilis, and possibly a Batrachoseps attenua- tus. Riithling also fed his captives on flies, beetles, moths, isopods, spiders, scorpions, centipedes, and bits of lettuce. The lettuce was tossed into the cage and was grabbed as it fell. Hibernation was noted by Riithling (1917) in captive specimens, which hid under pieces of bark that lay under a thick covering of dead leaves when cold weather arrived. They refused to eat but would occasionally emerge on warm winter days. Riithling (1917) observed that the colors and markings were more distinct when captive specimens were eating or were excited on a hot day. Ruthven (1907) records specimens of magister in the stomachs of Crotaphytus wislizenii, and suggests the road runner as a possible enemy. One specimen in the collection at Brigham Young Univer- sity was taken from the stomach of a Masticophis flagellum frenatus. Nematodes have been reported frequently in the stomachs or intes- tines, and I have observed a tapeworm in one. Wood (1935) reports on the intestinal protozoa. Locality records. TEXAS. BREWSTER co. : Glenn Springs (UM- MZ 66237-43); Boquillas (USNM 32939-40, 32942) ; between Chisos Mts. and Terlingua (KU 15070). EL PASO CO.: (UMMZ 53905; MCZ 31690, 7474; FMNH 1653; AMNH 15044; EHT 1; USNM 56860-2) ; Vinton (MCZ 12850) . REEVES CO. : Pecos (ANSP 15743-6) . COLORADO. MONTEZUMA co.: Southern Ute Indian Reservation, at intersection of Interstate Highway 666 and Mancos River (Barry, 1932). NEW MEXICO. DONA ANA co.: 15 mi. W of Las Cruces (AMNH 36841); Las Cruces (USNM 22269) ; Mesilla Valley (USNM 22382). HIDALGO CO.: near Lordsburg (KU 15987). OTERO CO.: Alamogordo (ANSP 1; AMNH 455-8). SIERRA CO.: below Her- mosa (MCZ 31681); Elephant Butte Dam (KU 11827-9). SOCORRO 156 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 CO.: Fort Craig (USNM 8663); Socorro Mts. (USNM 44592). VALENCIA co. : Las Lunas (KU 11823-4). UTAH. EMERY co. : Green River (UMMZ 61870-84); Lost Creek, San Raphael Desert (UU- 437); Straight Canyon, San Raphael Desert (UU 429-31, 433-4, 286-7). GRAND co.: near Moab (Tanner, 1934). IRON CO.: Cedar City (FMNH 21492). KANE CO.: Kanab and vicinity (UU 11; LMK 24890-1, 24893-915, 21153; KU 1; UMMZ 73271[2], 73272[3], 73273[2], 73274[3], 73275[5], 73277[3], 73280, 73278-9); Hall Cave (BYU 123, 930-7); Willasco Springs Tank, Escalante Desert (BYU 119, 912-6, 115, 901-5) ; Rock Creek (AMNH 57734, 57736). MILLARD CO.: 8 mi. N of Cove Fort (Knowlton and Thomas, 1934). WASHINGTON CO.: (AMNH 22928-9; MCZ 19152- 6); St. George (CAS 54216; MVZ 12245; UU 62-4; BYU 1920 [9], 1929, 2267, 3259[9], 3275, 3279, 3283; LMK 26666-8; USNM 18112- 3); 2 mi. S of St. George (LMK 22991-2); 4 mi. W of St. George (LMK 21077); 8 mi. N of Toquerville (UMMZ 60194[3]); between Rockville and Springdale (CAS 47817-28); Rockville (CAS 47829- 35; LMK 25598, 25664-5) ; Springdale (CAS 47811-6) ; Zion National Park (MVZ 18040-1; UU 221, 631: BYU 3908[7]); near Littlefield, Arizona (UU 510-2); Sham Smelter (UU 414); Beaver Wash (UU 415-6); Bloomington (UU 65; LMK 26665); Leeds (LMK 21076; USNM 44996); Anderson's Junction (LMK 23541); Pintura (LMK 23540); Grapevine Springs, Bellevue (AMNH 22917-9; USNM 36361-2); South Ash Creek, Bellevue (AMNH 22921-2); Diamond Valley, 10 mi. N of St. George (USNM 18114-5); Hurricane (Tanner, 1927) ; Middleton, Harrisburg, Mt. Carmel, Santa Clara, Washington (Knowlton and Thomas, 1934). WAYNE co.: Hanksville (UU 436); Cainville (UU 428); Notom, Pleasant Creek (CM 11556). SAN JUAN CO.: (FMNH 25279, 25454, 25527-9; UU 435; BYU 756, 759, 770, 809-10, 812-3, 816, 999; LMK 23593); Bluff City (AMNH 1359-60; UU 432, 717-9); San Juan Bridge Canyon, 3,250 ft. (FMNH 25526); Rainbow Bridge Trail (FMNH 23038[6]); Copper Canyon, 3 mi. NE of Needle Rock (MVZ 21798-9; AMNH 57737, 57739); John's Canyon, 26 mi. NW of Mexican Hat (UU 727); San Juan River, 15 mi. down from Zahn's Camp (AMNH 57735, 57742, 57740); Piute Rapids, San Juan River (AMNH 57732-3, 57743); Aztec Creek (AMNH 57731, 57738, 57741). NEVADA. CHURCHILL co.: Sand Spring (MCZ 34102); Hazen (AMNH 34102); 4-6 mi. W of Hazen (MVZ 15955; USNM 87025); Fallon (USNM 48691, 51901); 5 mi. N of Fallon (MVZ 20080-5); 10 mi. W of Fallon (MVZ 14364). CLARK CO.: mouth of Kyle Canyon, Charleston Mts., 4,000 ft. (UCLA 1169- 1939 MEXICAN LIZARDS SMITH 157 71); Kaolin, 1,200 ft. (MVZ 20666); Indian Spring, 4,000 ft., Virgin Mts. (MVZ 20074-7); 5 mi. N of Jean (LMK 7611); Piute Valley (LMK 7692); Crescent (SDSNH 15541); Callville (USNM 18104); Las Vegas Valley (USNM 18107); Indian Spring Valley (USNM 18108-9); Bunkerville (USNM 18111); Overton (Cowles and Bogert, 1936). ESMERALDA CO.: Fish Lake, 4,800 ft. (UMMZ 78012; MVZ 10818-20, 10822-4); 2 mi. NW of Cave Springs, 5,700 ft. (MVZ 10821); Columbus (USNM 18133). LINCOLN CO.: Caliente (CAS 37302-17); Meadow Valley, 21 mi. S of Caliente, 3,200 ft. (MVZ 13056); 16 mi. E of Groom Baldy, 4,600 ft. (MVZ 14215); 9 mi. E of Groom Baldy, 5,500 ft. (MVZ 13070); Crystal Spring, Pahranagat Valley (MVZ 14212-4, 14216-9, 14223-9, 14231); 2 mi. E of Crystal Spring (MVZ 14230); Ash Spring, 3,800 ft., Pahranagat Valley (MVZ 14220-2); 1 mi. W of Coyote Spring, 2,500 ft., Pahranagat Valley (MVZ 20078); Pahranagat Mt. and Valley (USNM 18096- 102). LYON CO.: Lincoln Highway, 22 mi. W of Fallon (MCZ 20086- 8). MINERAL CO.: Cat Creek, 4 mi. W of Hawthorne (MUZ 10858); 3 mi. S of Schurz (MUZ 17096-100). NYE CO. : Rhyolite (CAS 37515- 7); Railroad Valley, 11 mi. S of Lock's Ranch, Middle Stormy Spring, 5,000 ft. (MVZ 16217); Ash Meadows, 3.2 mi. WSW of Devil's Hole, 2,150 ft. (MVZ 16080-1; USNM 18105-6); 2 mi. SE of Fairbanks Spring (MVZ 20079) ; Amargosa River, 3.5 mi. NE of Beatty, 3,400 ft. (MVZ 13055, 13057-69) ; Pahrump Valley, 5,000 ft. (USNM 18103). WASHOE CO.: Derby and Wadsworth (LSJU 5876- 7, 5879, 5889-92); Truckee River, 12 mi. NW of Wadsworth (MVZ 16677); Wadsworth (USNM 50833); Pyramid Lake (KU 11704-7; LSJU 5880-1, 5883-4, 5886-8, 5874, 6282, 6292, 10 without number; CAS 40799-812, 40818-21, 40876, 44152-4; USNM 45201-6, 50808, 50810, 50831-2, 44785); Anaho Island, Pyramid Lake (CAS 40813- 7); The Willows, Pyramid Lake (USNM 50834); 4 mi. NW of Quite Indian Agency 3,900 ft. (MVZ 14425-6); Nixon (LSJU 7306[2]). ARIZONA. COCHISE CO.: Lewis Spring (AMNH 14927); 2 mi. NE of Lowell (MUZ 20536); Tombstone (FMNH 2771). COCONINO CO.: (FMNH 25715, 25739); flats 11 mi. SE of Kanab, Utah (UMMZ 73276[2]); below 8 mi. Gap, 11 mi. SE of Kanab (UMMZ 73281); Cameron (MVZ 17863; LMK 25666); 5 mi. W of Cameron (LMK 25667-8); 11 mi. W of Cameron (UMMZ 72654); Lee's Ferry (USNM 44995, 44998); 5 mi. S of Lee's Ferry (SDSNH 13055); Bright Angel Canyon (LMK 2168-72); Bright Angel Trail, Grand Canyon (MVZ 17578-9) ; Bright Angel Creek, 2,300 ft. (MVZ 17860- 2; SDSNH 13053; USNM 44997); Grand Falls, Little Colorado 158 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 River (UCLA 139; LMK 6023); Snake Gulch, Kaibab National Forest (UU 358) ; Roaring Springs, Grand Canyon (SDSNH 13073- 8, 13080-8, 13090-2, 13205-13); Flagstaff (MCZ 6805); Shimmo Creek and Bass Camp, 3,000 ft. Grand Canyon (USNM 59798-9) ; El Tovar (USNM 56857); Grand Canyon (USNM 15849-50); Supai Springs (USNM 79698); Jacob's Pools (USNM 44999). GILA CO.: 3 mi. NW of Globe (UMMZ 75691); 16 mi. W of Miami (KU 11825; EHT 1); Roosevelt Lake (USNM 54594-6); McMillanville (USNM 54659). GRAHAM CO.: Camp Grant (USNM 24559); east base of Gila Mts. (SDSNH 14057). MARICOPA CO.: (USNM 61388) ; Phoenix (KU 12444; USNM 58669); Cave Creek, 25 mi. NE of Phoenix (KU 12325; CAS 17287-9, 20718); Winter's Wells, 50 mi. W of Phoenix (CM 1411-2); Gila Bend (KU 11707; SDSNH 14844-6; USNM 61402, 61439); 6 mi. N of Gila Bend (SDSNH 14849, 15480-1); Mesa (UMMZ 75689[3], 75690; LMK 25603); Paradise Valley (CAS 17286); Tempe (LSJU 3172-3); Wickenburg (USNM 73733). MOHAVE CO.: Yucca (AMNH 9245); 10 mi. N of Wolf Hole (MVZ 16391); 25 mi. above dam, Boulder Lake (MVZ 19250); Toroweap Valley, 4,000 ft. (MVZ 16392-5); Beaver Dam Wash, Littlefield (UU 494); Pipe Springs (LMK 24885-9; UU 477; SDSNH 13054); 26 mi. N of Chloride (LMK 10630-1); Chemehuevis Mts. (LAM 445-7); Big Sandy River (USNM 60214, 45149); Hackberry (USNM 60215-7); Topock (USNM 60222-3); mouth of Diamond Creek, 1,500 ft. (USNM 60224-5); Bill Williams River (USNM 45056); 8 mi. NE of Needles (USNM 45147); Ft. Mohave (USNM 42098). NAVAJO CO.: Winslow (FMNH 936[2]); 2 mi. N of Agathla Peak, Kayenta Creek (MVZ 17864-5). PIMA CO.: (AMNH 26739, 27641); Tucson (UMMZ 53946, 65091[3]; CAS 34054, 34057; ANSP 11880; AMNH 489; USNM 16937, 16964-7, 17236-9, 56858); 6 mi. N of Tucson (AMNH 26718); 16 mi. S of Tucson (KU 13141-2); 20 mi. SW of Tucson (KU 13139-40); Steam Pump (AMNH 26692-3, 26695-8, 26703, 26707, 26710, 26712-3, 26717, 26724); Catalina Mts. (CAS 34174-5, 34302-3, 34309-14, 34318-9, 48484-5); Sabino Canyon, Santa Catalina Mts. (KU 6949-50) ; W end of Catalina Mts. (UMMZ 69887) ; Kelly Ranch, Catalina Mts. (UMMZ 69881, 69884- 6); Ft. Lowell (LSJU 638-9, 642, 803, 2523, 2570); between Ajo and N end of Growler Mts. (UMMZ 69888); 6 mi. NE of Ajo (UM- MZ 69858); Sells (UMMZ 68455); Santa Rita Mts. (CAS 48483); Tanque Verde Ranch (SDSNH 16123-5); Roeble's Ranch, near Coyote Springs (ANSP 17471). FINAL CO.: Florence (KU 15544-5); 29 mi. SE of Florence (MVZ 7781); between Florence and Mineral 1939 MEXICAN LIZARDS SMITH 159 Mt. (SDSNH 14847-8); Oracle (LMK 22879); Casa Grande (LAM 195-6); Coolidge (LAM 683); 1 mi. N of Willow Spring (AMNH 26708); Superior (MCZ 12476); Price (USNM 54675). SANTA CRUZ CO.: below Sawmill Canyon, Santa Rita Mts. (CAS 63055); Tubac (SDSNH 14813-8, 14820, 14834, 14839-41, 14843). YAVAPAI CO.: Fort Verde (AMNH 1346-7, 1349, 1358; USNM 14815); Congress Junction (LMK8373;USNM 54664) ; Yarnell (LMK8375); Kirkland (USNM 54678); Camp Verde (USNM 59797); Montezuma Well (USNM 59792); Seligman (USNM 45036). YUMA CO.: (USNM 61396); 6 mi. NE of Yuma (UMMZ 69889); Yuma (LSJU 1071-3; CAS 33488-9; ANSP 17483; MCZ 26684-5; USNM 2967, 15952-4, 15957-9, 15965, 37656-8, 46220-2, 47934); between Wellton and Tinajas Altas (UMMZ 71115-6); Tinajas Altas (USNM 21794); Gonzales Well (MVZ 7780); Gila River Valley N of Stoval (SDSNH 14056); Castle Dome (SDSNH 16732); Parker (USNM 16803). CALIFORNIA. FRESNO CO.: Los Gatos Canyon (LSJU 633); Coalinga (CAS 13206); Kettleman Hills (MVZ 18061); 4 mi. E of Coalinga (MVZ 18062); Stanley, 8 mi. W of Huron (USNM 44808-10). IM- PERIAL CO.: Hanlon's Ranch (CAS 33443-5); Yuma Indian Reserva- tion (CAS 33419-21); Holtville (MVZ 4809); Silsbee (MVZ 997); Pilot Knob (MVZ 1848-9) ; 5 mi. N of Laguna (MVZ 1847) ; 3 mi. N of Bard (SDSNH 14053-4); Potholes (SDSNH 14055); Palo Verde (LAM 42, 628[2]); Ft. Yuma (USNM 21909-10, 10513); Calexico (USNM 37125); Unlucky Lake, New River (USNM 21911); Laguna Station, Unlucky River (USNM 21912). INYO CO.: Lone Pine (MCZ 10999-11004; FMNH 1237[2]; LSJU 634; USNM 18131-2); Emigrant Canyon (FMNH 1210); Emigrant Pass (LMK 22221-3); Nemo Canyon, Panamint Mts. (CAS 65321-2); Wildrose Canyon, Panamint Mts., 4,000 ft. (MVZ 19249, 6624-6) ; Willow Creek, Pana- mint Mts. (Grinnell and Camp, 1917); Panamint Mts. (USNM 18116-9); Bruce Canyon, Argus Mts. (CAS 65483); Shepherd Can- yon, Argus Mts. (USNM 18128-30); Searl's Canyon, Argus Range (Stejneger, 1893); (?)Cottonwood Canyon (USNM 9488); Grape- vine Mts., 4,000 ft. above Salt Wells, Mesquite Valley (USNM 18110); Independence (MVZ 9460); Mazourka Canyon, Inyo Mts. (MVZ 3686); Little Lake, 3,100 ft. (MVZ 6787-8); Sulphur Springs, 6 mi. N of Shoshone (SDSNH 15866); Stovepipe Wells (SDSNH 15873); between Olancha and Cowan Station (SDSNH 12235-8); Keough Hot Springs (SDSNH 12239). KERN CO.: Mohave (CAS 35467; MVZ 2964); Kern River at Bodfish (MVZ 2951); Weldon, 2,650 ft. (MVZ 2953-63); Onyx, 2,750 ft. (MVZ 2946-50); 5 mi. 160 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 E of Onyx (MVZ 2952); Walker Pass (LMK 5732; USNM 18120-2); La Rosa (LMK 8791); 11 mi. N of Randsburg (SDSNH 12240-1); Lonesome Camp (SDSNH 12242). LOS ANGELES CO.: (AMNH 57758-63; AMNH 59118-23); Fairmont (AMNH 9205; UCLA 302 [4]; CAS 48993-7; MVZ 732-3, 833-5; LAM 255-8; USNM 69734- 45); Neenach (FMNH 23595-6; LMK 22072-4); Lovejoy Springs (UCLA 136-8; LMK 2831-2; LAM 708[2]); 4 mi. W of Fairmont (UCLA 412); Vasquez Rocks (UCLA 600); 44 mi. E of Palmdale (MVZ 16277-8); Palmdale (LMK 22075-9; LAM 360-2); Antelope Valley (LMK 732-3; CM 4046; USNM 69746-8, 54809-11, 54835); Lovejoy Buttes (LMK 1933-6, 2440-1); Rattlesnake Canyon (LAM 1); Pallett (Grinnell and Camp, 1917). RIVERSIDE CO.: Banning (UMMZ 70788); Gavilan (LSJU 5477-80, 5482-92); San Bernardino Mts. (CAS 43211); Cottonwood Springs (CAS 33343-4, 64676); Mecca (CAS 33333, 45376; MVZ 410, 466-8); 35 mi. E of Mecca (Cowles, 1920); Palm Springs (MVZ 12420-4; SDSNH 12102; USNM 22773); Carrizo Creek, Santa Rosa Mts., 2,000 ft. (MVZ 488, 490); Cabezon, San Jacinto Mts. (MVZ 180, 188); 6 mi. N of White- water Junction (LMK 8522); Thousand Palms (LMK 22491, 7797; SDSNH 12084-95); Cahuilla Valley (LSJU 800); Desert Center (LMK 5001-2); Box Canyon (LMK 7796); Andreas Canyon, San Jacinto Mts. (LAM 297). SAN BENITO CO.: 2 mi. SE of Panoche (MVZ 21206-9); Panoche Creek, 1,000 ft, 4 mi. E of Panoche (MVZ 16051, 21354). SAN BERNARDINO CO.: Victorville (UMMZ 56073-4; MCZ 31715; LSJU 5421, 6414; CAS 42827-36; MVZ 819-30, 5377; LAM 374); Apple Valley, 6 mi. E of Victorville (LMK 10635-6); 6 mi. W of Victorville (LMK 7043); 18 mi. SE of Victorville (MVZ 11194); Pilot Knob (FMNH 1246); Hesperia (AMNH 9246; KU 12443; CAS 42872; SDSNH 11381-4, 11207, 11508); Ludlow (CAS 42624); Barstow (CAS 36162-3, 42688-90; LMK 3561-4); Turtle Mts. (CAS 42293-302) ; Horn Mine, E base of Turtle Mts. (MVZ 15475-9); Cushenbury Springs 4,000 ft. (MVZ 730-1, 832); 3 mi. E of Two Springs (MVZ 18028); Needles (MVZ 1130-1; USNM 44620) ; W of Topock, Arizona (MVZ 1132) ; Cajon Pass (LMK 5721- 5); Adelanto (LMK 5726-7); Kramer Hills (LMK 5728-9, 5733-4); Thorn (LMK 10637); Deadman Point (LMK 10632^); Stoddart Well (LMK 20889); Wheaton Spring (LMK 7612); Yucca Station (LMK 7613). SAN DIEGO CO.: (USNM 16522); Jacumba (CAS 40043); 6 mi. E of Jacumba (UMMZ 69859[6]); Boulder Park (KU 12442; LMK 3230-1); San Felipe Creek (CAS 62784-7); Mason Valley (CAS 62872-3); La Puerta (MVZ 1054, 9240-4; LMK 581; 1939 MEXICAN LIZARDS SMITH 161 SDSNH 16540, 11311-8, 11333-6, 11415; LAM 76[2]); Warner Pass (MVZ 1032); Yaqui Well (LMK 22330); Collins Valley (SDSNH 11944, 11972); The Narrows (SDSNH 11953); Boulevard (USNM 59361). LOWER CALIFORNIA. Matomi (FMNH 1065[2]); Las Palmas Canyon, 200 ft., N side of Laguna, 15 mi. S of California Line (MVZ 10724); El Mayor, 30 ft. Hardy River (MVZ 9544; LMK 10304) ; 7 mi. E of Cerro Prieto, 30 ft. (MVZ 10755-6) ; Las Palmitas, S base of Sierra Juarez (SDSNH 17053); Gardner's Laguna (USNM 21913-5); Cook's Wells, Salton River (USNM 21916-7); Volcano Lake (USNM 37659-60); Cocopah Mts., E base (USNM 37663); San Felipe Bay (USNM 37664). SONORA. Camoa (USNM 46846); Patomotal (USNM 47264); Carbo (LMK 2881-2); Guaymas (LMK 4068); San Carlos Bay, NW of Guaymas (EHT 8336-8); Toban Bay (LMK 4066); Tiburon Is. (CAS 53356-9); Noria (EHT 8341-2); Miramar (EHT 8335, 8339). CHIHUAHUA. Between El Paso and Janos (USNM 2964). DURANGO. Near Yermo (EHT 8334). Sceloporus magister rufidorsum Yarrow. Sceloporus clarkii zosteromus Lockington, Amer. Nat., 14, p. 295, 1880. Sceloporus rufidorsum Yarrow, Proc. U. S. Nat. Mus., 5, pp. 442-443, 1882 (part); Van Denburgh and Slevin, Proc. Calif. Acad. Sci., (4), 11, p. 396, 1921; Schmidt, Bull. Amer. Mus. Nat. Hist., 46, pp. 661, 663, 1922; Van Denburgh, Occ. Papers Calif. Acad. Sci., 10, pp. 338-341, 1922; Stejneger and Barbour, Check' List N. Amer. Amph. Kept., 2nd ed., p. 58, 1923; Slevin, Proc. Calif. Acad. Sci., (4), 15, p. 204, 1926; Stejneger and Barbour, Check List N. Amer. Amph. Kept., 3rd ed., p. 64, 1933; Ditmars, Kept. N. Amer., p. 59, 1936. Sceloporus zosteromus Van Denburgh, Proc. Calif. Acad. Sci., (2), 5, p. 1004, 1896; idem, (3), 4, pp. 3, 23, 25, 26, 1905 (part); Meek, Field Mus. Nat. Hist., Zool. Ser., 7, p. 11, 1905 (part); Van Denburgh and Slevin, Proc. Calif. Acad. Sci., (4), 4, pp. 132, 144, 145, 148, 1914 (part). (l)Sceloporus clarkii Terron, Mem. Soc. Cient. "Antonio Alzate," Mexico, pp. 165, 167, 1921. Sceloporus magister rufidorsum Linsdale, Univ. Calif. Publ., Zool., 38, p. 366, 1932 (part); Burt, Amer. Mid. Nat., 14, p. 237, 1933; Mosauer, Occ. Papers Mus. Zool. Univ. Mich., 329, pp. 3, 9, 15, 1936. Sceloporus clarkii rufidorsum Burt, Trans. Kans. Acad. Sci., 38, p. 275, 1936. Type locality. San Quintin Bay, Lower California. Type USNM 11981, collected by Belding. Distribution. Northern Lower California exclusive of the north- eastern section, southward to include the Vizcaino Desert; Cerros Island (fig. 13). 162 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 Diagnosis. A Sceloporus of rather large size, maximum snout- vent measurement about 131 mm.; dorsal scales 27 to 31, average 28.5; ventral scales 37 to 46, average 41.2; scales around body 32 to 37, average 33.9; femoral pores 14 to 21, average 17.5; dorsal scales keeled, strongly mucronate; supraoculars usually six, the last two broadly in contact with median head scales; first canthal in contact with lorilabials; no oblique dark lines on sides of body; belly patches confluent in large males; a narrow, light band down middle of back, bordered on either side by a dark band or a series of dark spots; dark shoulder patch with a light posterior border. Color. General dorsal ground color in large males, dark reddish brown; head dark chocolate color; a light, indefinitely outlined, straw yellow median band one and two half scale rows wide extending from shoulder region to base of tail; on either side of this a dark brown, indefinitely outlined band, about two and two half scale rows wide; sides of neck and abdomen, below these dorsal bands, of a dull purple hue, with numerous, scattered, irregularly outlined, white or pale blue spots; these spots usually on the free edges of the scales, one to a scale; the limbs dark reddish brown, the tips of some of the scales white; toes and limbs sometimes with indistinct bands; tail with faint, narrow, alternating light and dark bands. The entire ventral surface of the abdomen (except a few irregular light areas in middle) a broad area at the posterior part of the throat, the anterior surfaces of the arms, the ventral surfaces of the thighs and a large area on the ventral surfaces of the shank more or less uniform navy blue; the centers of some of the scales on the sides of the abdomen (in some specimens) paler blue; the dark blue color of the abdomen extending dorsad a short distance onto the sides of the body; a small area at the extreme median anterior surface of the chest white or pale blue; a large black area in front of arm, extending into nuchal pocket, continuous with the dark color of the median gular area; shoulder spot bordered posteriorly by a distinct, vertical white band; extreme anterior part of gular area cream color, becoming pale blue near middle of throat, the color blending posteriorly with the dark color of the posterior gular region; narrow, dark blue lines extending forward from the posterior gular area along the edges of the scale rows; ventral surface of tail white or cream color. Smaller males (90 to 100 mm. snout to vent) are identical with the larger specimens (measuring 115 mm. or more), except for a broken, irregular light area on middle of abdomen, extending from a point even with the axillae to the interfemoral region. Males measur- 1939 MEXICAN LIZARDS SMITH 163 ing 60 to 65 mm. show irregular bluish markings on the sides of the abdomen and posterior gular region; the throat is faintly barred; the sides of the body have faint dark brown vertical bands; the areas occupied by the dark bands adjacent to the median light band are replaced by two series, one on each side, of eleven dark brown, more or less square blotches, faint posteriorly on body, distinct anteriorly. There is no evidence of a dorsolateral light stripe or of dark bands along the edges of the lateral scale rows. The very young are similar to the young males described above. The median dorsal band is visible and narrow in all. In the larger males the dark blotches tend to fuse into bands. The ventral sur- faces of females are immaculate, or with irregular blotches on the chest, the throat sometimes faintly barred, with sometimes a bluish spot at the posterior edge of the gular area. Specimens from Cerros Island are definitely referable to this sub- species. There is no evidence of a lined pattern on the limbs or the sides of the body; the median dorsal stripe is present and narrow. The only difference between these and the northern specimens is the definite development of a darker blue median border on the lateral belly patches in males; the belly patches are also of a lighter hue. This differentiation of a darker median border does not occur in typical m. rufidorsum (though a slight indication may be observed in some young specimens from the northern half of the peninsula). Variation. The following data have been taken from 51 speci- mens (unless otherwise stated). Parietals two in all; frontoparietals single on each side in all; frontal touches interparietal in 47, separated by an azygous scale in one, by contact of frontoparietals in three; posterior section of frontal transversely divided in one, anterior section similarly divided in one; superciliaries five or six (6, eighty- eight; 5, fourteen) ; supraoculars five to seven (5, three; 6, one hundred and forty-six; 7, three); last two supraoculars contact median head scales in all; prefrontals contact in all; median frontonasal separated from lateral frontonasal in one; internasals more or less similar to m. magister; subnasal absent on both sides in seven, on one side in one; first canthal separated from lorilabials in one; preocular divided on one side in four, on both sides in two; two loreals on both sides in one, no loreal in one (fused with preocular) ; lorilabials reduced to one row below subocular by contact of one or more scales with both sub- ocular and supralabials on one side in four, on both sides in two; outer row of labiomentals separated from mental in none of those observed (20). 164 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 Dorsal scales 27 to 31, average 28.5 (51 counts: 27, eleven; 28, ten; 29, twenty-two; 30, seven; 31, one); ventral scales 37 to 46, average 41.2 (51 counts: 37, two; 38, four; 39, six; 40, nine; 41, six; 42, nine; 43, six; 44, six; 45, two; 46, one); scales around body 32 to 37, average 33.9 (50 counts: 32, ten; 33, twelve; 34, eleven; 35, ten; 36, five; 37, two). Femoral pores 14 to 21, average 17.5 (167 counts: 14, four; 15, eight; 16, twenty-three; 17, fifty-three; 18, forty-two; 19, twenty-three; 20, ten; 21, four). Specimens with pore counts of fourteen and fifteen are from Cerros Island (14-15, 15-16, 15-17) and San Jose" (14-14, 14-15). S. m. magister in Lower California shows no strong tendency in femo- ral pore count toward the averages in m. rufidorsum. Counts for eight m. magister from various localities in Lower California are: 11-12, 12-12(3), 12-13(2), 13-13, 13-14. The specimens with five supraoculars are from El Rosario (5-5) and Cerros Island (5-6). The specimens of m. magister with six and seven supraoculars are from Texas (three, 5-6; one, 6-6), Utah (two, 5-6; one, 6-6), Arizona (5-6; two, 6-6), and California (6-7, 6-6). The two latter speci- mens (from vicinity of Jacumba) are very small and may not be normal. So far as I am aware, intergradation between m. magister and m. rufidorsum has not been demonstrated; however, as the char- acters used to separate the two forms overlap somewhat, and because of a very definite similarity in peculiar characters not occurring normally elsewhere in the genus, I have considered the two as subspecies. Locality records. Abreojos Point (CAS 55817) ; Arroyo Calentura (LMK 6103-4); Catavifia (UMMZ 76484); Cerros Island (UMMZ 70790; MCZ 14318-20; FMNH 18409; USNM 11971, 15159, 23885, 24411, 23865, 23867, 23876-8, 23880, 23887, 64473, 71653; AMNH 5475-6; CAS 8842, 8852-7, 56142-50, 59569-76; MVZ 9691-4; LMK 5224-33, 5234-5, 7250-1, 24301-11; SDSNH 15907-17); Colnett (LMK 2883); El Rosario (MVZ 13559-75); Ensenada (UMMZ 57499; USNM 37661-2; AMNH 18342; CAS 8533-7, 8539- 40, 6561, 8594-8600, 8622, 8627-31); 4-8 mi. S of Ensenada (CAS 57583; LMK 23696, 23716; SDSNH 11549); Punta Prieta (UCLA 444); Rosarito (FMNH 1066); San Angel (WM 4); San Fernando (USNM 21538); San Jose" (CAS 65777; LMK 4062); 3 mi. W of San Jose*, San Pedro Martir Mts. (CAS 57486) ; San Pedro Martir foothills (LSJU 693-4); San Quintin (FMNH 1126[4]; CAS 55803-7); San Quintin Bay (USNM 11981, 11979); San Ramon (MVZ 9727, 9885-6); San Raphael (USNM 16853-4); San Telmo (LSJU 695-9; 1939 MEXICAN LIZARDS SMITH 165 MVZ 9728-30); Santa Teresa Bay (LMK 4061); Socorro (UMMZ 77073; MVZ 13576); Socorro, 15 mi. S of San Quintin Bay (USNM 21500); Turtle Bay (S of San Bartolome Bay) (CAS 59392; LMK 4060). Sceloporus magister monserratensis Van Denburgh and Slevin. Sceloporus zosteromus Mocquard, Nouv. Arch. Mus. Hist. Nat. Paris, (4), 1, pp. 313-314, 1899 (part); Van Denburgh, Proc. Calif. Acad. Sci., (3), 4, pp. 3, 23, 25, 26, 1905 (part); Van Denburgh and Slevin, Proc. Calif. Acad. Sci., (4), 4, pp. 132,144, 145, 148, 1914 (part) ; Schmidt, Bull. Amer. Mus. Nat. Hist., 46, pp. 661-662, 663, 1922 (part); Slevin, Proc. Calif. Acad. Sci., (4), 15, p. 204, 1926. Sceloporus monserratensis Van Denburgh and Slevin, Proc. Calif. Acad. Sci., (4), 11, p. 396, 1921; Schmidt, Bull. Amer. Mus. Nat. Hist., 46, p. 662, 1922; Van Denburgh, Occ. Papers Calif. Acad. Sci., 10, pp. 342-344, 1922; Stejneger and Barbour, Check List N. Amer. Amph. Kept., 2nd ed., p. 57, 1923; Barbour and Loveridge, Bull. Mus. Comp. Zool., 69, p. 335, 1929; Stejneger and Barbour, Check List N. Amer. Amph. Kept., 3rd ed., p. 63, 1933; Ditmars, Kept. N. Amer., p. 59, 1936. Sceloporus magister rufidorsum Linsdale, Univ. Calif. Publ., Zool., 38, p. 366, 1932 (part). Type locality. Monserrate Island, Gulf of California. Type CAS 50509, collected by Joseph R. Slevin. Distribution. Southern edge of the Vizcaino Desert in Lower California, southward to the southern end of the Sierra de la Gigantea; islands adjacent to the coast in the Gulf of California except Santa Catalina (fig. 13). Diagnosis. A large Sceloporus, maximum snout-vent measure- ment 108 mm.; dorsal scales 27 to 32, average 29; ventral scales 37 to 49, average 42.6; scales around body 31 to 39, average 34.8; femoral pores 17 to 24, average 20; dorsal scales keeled, strongly mucronate; six or seven supraoculars, the last two (seldom only the last) in contact with median head scales; outer row of labiomentals usually in contact with mental; first canthal in contact with lorilabials. Lateral scale rows (in adult males) with more or less continuous, oblique, dark lines; belly patches not confluent; a narrow, median dorsal, light band, bordered on each side by a series of dark spots or (in adult males) by a dark band; dark shoulder patch with a light posterior border. Color. The markings are in general similar to those of m. rufi- dorsum, with the following exceptions: the edges of the scale rows on the sides of the body and, in males, on the sides of the neck, have a dark streak; most of the chest and a continuous, median ventral 166 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 abdominal streak are white (males); sides of belly pale lavender, with a distinct dark blue median border extending into groin and, in the largest males, onto the thighs; this border sometimes con- tinuous over chest, and uniting with the black shoulder patches; ventral surfaces of shank immaculate except in largest males; usually in the females, always in the males, the scale rows on the limbs have a median light streak. Most of the young show no lined pattern on the sides of the body; however, all of the adults (except some females) show a distinct lined pattern. The limbs of the young are lined. The females are similar in ventral coloration to those of m. rufi- dorsum, except that there is a stronger development of the male color characteristics: the throat patch is more distinct than in females of m. rufidorsum, and the lateral abdominal marks, including the median dark blue border, are more in evidence. There is a tendency in these toward the development of the lateral dorsal dark bands, resulting from coalescence of the two series of dark spots. The dark spots are in evidence in the young, however, and in most of the females; in the adult or subadult males the spots are replaced completely by bands. In a few adult males the median dorsal light streak is but little in evidence; I believe this may be due to loss of the scales. In all others the median light band is distinct. Variation. The following data have been taken from 62 speci- mens, unless otherwise stated. Two parietals in all; two fronto- parietals on both sides in one, on one side in another; frontal touches interparietal in 51, separated by an azygous scale in three, by contact of frontoparietals in eight; posterior or anterior section of frontal divided into two or more scales in seven; seven superciliaries on one side in one, six in others; supraoculars five to seven (5, one; 6, one hundred and seven; 7, sixteen); last supraocular only in contact with median head scales in eight, last two in 54; pref rentals contact medially in 51, separated by an azygous scale in two, by contact of frontal and median frontonasal in nine; internasals more or less as in m. magister; subnasal absent on both sides in six, on one side in one; first canthal touches lorilabials in all; preocular divided on both sides in one, entire in others; loreal single in all; two postrostrals in one, five in one, four in 60; lorilabials reduced to one row below sub- ocular by contact of one or more scales with both subocular and supralabials on one side in four, on both sides in three; labiomentals narrowly separated from mental on one side in three, on both sides in eight (32 observed). 1939 MEXICAN LIZARDS SMITH 167 Dorsal scales 27 to 32, average 29 (60 counts: 27, seven; 28, seventeen; 29, twelve; 30, sixteen; 31, seven; 32, one); ventral scales 37 to 49, average 42.6 (60 counts: 37, one; 38, two; 39, three; 40, nine; 41, eight; 42, five; 43, eight; 44, six; 45, seven; 46, five; 47, three; 48, one; 49, two); scales around body 31 to 39, average 34.8 (60 counts: 31, two; 32, three; 33, thirteen; 34, fifteen; 35, six; 36, ten; 37, six; 38, four; 39, one). Femoral pores 17 to 24, average 20 (190 counts: 17, seven; 18, twenty-seven; 19, forty; 20, forty-five; 21, forty-one; 22, twenty-one; 23, five; 24, four). Remarks. S. magister monserratensis is here considered as the occupant of the middle faunal zone of Lower California, and is not restricted to Monserrate Island. Until recent years but little material has been available from the central faunal zone which accounts for 60 50 40 30 20 10- M MAGISTER M.RUFIOORSUM M. MONSERRATENSIS 10 II 12 13 14 15 16 17 18 19 20 21 22 23 24 FIG. 14. Variation in number of femoral pores in Sceloporus m. magister, S. m. rufidorsum, and S. m. monserratensis. the varied treatment in the past of what specimens were available. It appears obvious that the form differs from m. rufidorsum, and that the break occurs where I have placed it (southern boundary of Vizcaino Desert). Femoral pore counts as well as coloration bear this out. The Monserrate Island specimens differ from m. rufi- dorsum in exactly the same characters as the specimens from the central mainland region; I can discern no differences between the island and central mainland specimens. It is true that the essential color differences between m. rufi- dorsum and m. monserratensis are evident mostly in adult males; the young and females may not have the color pattern so distinct. There are three major differences in color pattern: sides of body with narrow dark lines; belly patches in males not confluent, with a narrow, dark, medial edge; females with rather distinct ventral markings similar to those in males. In the possession of a narrow, median dorsal light band bordered on either side by a series of dark spots or by a dark band, m. monserratensis agrees with m. rufidorsum, 168 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 but differs from m. zosteromus, which has completely lost the two dorsal series of dark spots, or the dark bands (spots visible in very young). S. m. zosteromus differs from m. monserratensis also in average femoral pore count, though the difference is less than that between m. monserratensis and m. rufidorsum. S. m. zosteromus agrees with m. monserratensis in possessing the dark, oblique lines on the sides of the body. In femoral pore counts, 22.2 per cent of m. rufidorsum have 19 or more pores on a side, while 82.1 per cent of m. monserratensis have 19 or more pores on a side. Locality records. LOWER CALIFORNIA: Coast of Lower California (USNM 14089 [2]); Comondu (FMNH 25846, 25848-9; MVZ 13589- 90); between Comondu and Loreto (USNM 67387-91); El Medano (MVZ 13609-10); Loreto (FMNH 25847); Monserrate Island (MCZ 16840; CAS 50509, 52256-78); Mulege (Muleje") (Mocquard, 1899); Pt. Santa Antonita, San Nicolas Bay (CAS 53623); Puerto Escondido (CAS 53635); San Ignacio (WM 3; UMMZ 76483 (16); MVZ 10650-2, 10655, 10657-8, 13593-6, 13598, 13600-6; LMK 4055-9; USNM 37666-9); San Jorge (MVZ 13607-8); San Jose* Island (CAS 52687-92; MVZ 11726-7; LMK 4063^, 6848-9); Santa Magdalena Island (CAS 55933-97, 59361-88; MVZ 13611-7; LMK 10251, 10693; USNM 71629-30); Santa Margarita Island (CAS 56086-104; MVZ 13618-22; LMK 4065). Sceloporus magister lineatulus Dickerson. Sceloporus lineatulus Dickerson, Bull. Amer. Mus. Nat. Hist., 41, pp. 467-468, 1919; Van Denburgh and Slevin, Proc. Calif. Acad. Sci., (4), 11, p. 396, 1921; Nelson, Mem. Nat. Acad. Sci., 16, pp. 114, 115, 1922; Schmidt, Bull. Amer. Mus. Nat. Hist., 46, p. 662, 1922; Van Denburgh, Occ. Papers Calif. Acad. Sci., 10, pp. 345-347, 1922; Stejneger and Barbour, Check List N. Amer. Amph. Kept., 2nd ed., p. 56, 1923; idem, 3rd ed., p. 62, 1933; Ditmars, Kept. N. Amer., p. 59, 1936. Type locality. Santa Catalina Island, Gulf of California. Type USNM 64263. Distribution. Known only from Santa Catalina Island, Gulf of California (fig. 13). Diagnosis. A large Sceloporus, maximum snout-vent measure- ment 115 mm.; dorsal scales strongly mucronate, keeled, 28 to 31 from occiput to base of tail; femoral pores 17 to 20; supraoculars five or six, the last two in contact with median head scales; first canthal in contact with lorilabials; outer row of labiomental scales separated from mental, or in contact; belly patches confluent in 1939 MEXICAN LIZARDS SMITH 169 adults; shoulder patch not light-bordered posteriorly; females colored exactly like males below. Color. "The color above, in adult males, is yellowish brown, becoming browner on the hind limbs and base of tail. A few of the scales of the back are marked with greenish blue in varying amount. The scales on the base of the tail are not spotted but those on the hind limbs often are marked centrally with yellowish or bluish gray. The scales on the base of the tail usually are edged with yellow. There is no well-developed longitudinal light streak along the middle of the back but this region is lighter than the rest of the body. There is no dorsolateral longitudinal light band, even on the neck. The sides of the body are bluish or grayish with more or less parallel narrow, dark lines running in the direction of the keels of the lateral scales. These lines are formed by from one to three dark brown or blackish lines on each scale. The central area of each lateral scale is bluish or grayish. The top of the head is brownish olive, usually without markings. There is a large, black blotch or collar in front of the shoulder, sometimes indistinctly edged behind and in front with pale blue or greenish yellow. There is a similar but smaller black blotch on the anterior and ventral surfaces of the thigh and of the body. These two black blotches may be connected by a black streak along the belly just external to a median longitudinal stripe of yellowish white, but in most specimens the entire median portion of the belly is black. This black ventral area extends forward onto the chest, where it is more or less tinted with, or replaced by, spots of greenish blue. The central gular region is blackish indigo, while on the chin and anterior gular region the scales are lighter indigo with lighter blue centers which may form parallel longitudinal blue lines separated by darker ones. The upper surfaces of the limbs are yellowish brown or olive, usually with longitudinal dark and light streaks. The tail rarely is faintly crossbarred above with brown. "Females and young males are similarly colored, and do not have more evident dorsal dark spots or light dorsolateral lines." (Van Denburgh, 1922, pp. 346-347.) Variation. The variation in cephalic scutellation of 10 specimens is as follows: parietals two in all; frontoparietals single in all; frontal touches interparietal in all; five superciliaries on one side in three; five supraoculars in seven counts, six in 13; prefrontals in contact in all; one pair of internasals in nine, one and one half pairs in one; sub- nasal absent on both sides in three, on one side in one; outer row of labiomentals contacts mental in five. 170 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 Dorsal scales 28 to 31 (28, one; 29, four; 30, four; 31, one) ; ventral scales 38 to 42 (38, one; 39, three; 40, two; 41, one; 42, two); scales around body 30 to 33 (30, one; 32, four; 33, five). Femoral pores 17 to 20 (17, two; 18, two; 19, six; 20, ten). Remarks. S. m. lineatulus is quite similar to m. monserratensis and m. zosteromus; it differs from the former in not having a narrow median dorsal light streak; it differs from both in lacking a light posterior edge on the black shoulder patches. Specimens examined. Santa Catalina Island (MCZ 32429; AMNH 5477; USNM 64263; LMK 6847; CAS 52311-9). Sceloporus magister zosteromus Cope. Sceloporus zosteromus Cope, Proc. Acad. Nat. Sci. Phila., 1863, p. 105, 1863; idem, 1866, p. 312, 1867; Bocourt, Jour. Zool., Paris, 5, p. 402, 1876; Garman, Bull. Essex Inst., 16, p. 17, 1884; Cope, Proc. Amer. Phil. Soc., 22, pp. 395, 399, 1885; Boulenger, Cat. Liz. Brit. Mus., 2, pp. 218, 225-226, 1885; Cope, Bull. U. S. Nat. Mus., 32, p. 37, 1887; idem, Proc. U. S. Nat. Mus., 12, p. 147, 1889; Stejneger, N. Amer. Fauna, 7, pp. 178, 181, pi. 1, figs. 3 a-c, 1893; Van Denburgh, Proc. Calif. Acad. Sci., (2), 5, pp. 79, 82, 108-110, 113, 1895; Cope, Amer. Nat., 30, p. 1013, 1896; Boulenger, Proc. Zool. Soc. Lond., 1898, p. 915, 1898; Mocquard, Nouv. Arch. Mus. Hist. Nat. Paris, (4), 1, pp. 313-314, 1899 (part); Cope, Ann. Kept. U. S. Nat. Mus., 1898, pp. 337, 338, 339, 356-8, fig. 53, 1900; Ditmars, Kept. Book, pp. 128, 133, 1907; Lydekker, in Lydekker [and others], Kept. Amph. Fish., p. 79, 1912; Stejneger and Barbour, Check List N. Amer. Amph., p. 57, 1917; Dickerson, Bull. Amer. Mus. Nat. Hist., 41, p. 468, 1919; Terron, Mem. Soc. Cient. "Antonio Alzate," Mexico, 39, 165, 167, 1921; Van Denburgh and Slevin, Proc. Calif. Acad. Sci., (4), 11, p. 396, 1921; Nelson, Mem. Nat. Acad. Sci., 16, pp. 114, 115, 1922; Schmidt, Bull. Amer. Mus. Nat. Hist., 46, pp. 661-662, 663, 1922 (part); Van Denburgh, Occ. Papers Calif. Acad. Sci., 10, pp. 348-352, 1922; Stejneger and Barbour, Check List N. Amer. Amph. Kept., 2nd ed. p. 59, 1923; idem, Check List N. Amer. Amph. Kept., 3rd ed., p. 65, 1933; Ditmars, Kept. N. Amer., pp. 47, 51-52,1936. Sceloporus clarkii zosteromus Cope, Bull. U. S. Nat. Mus., 1, pp. 49, 93, 1875; Coues, U. S. Geog. Surv. W. 100th Mer., 5, p. 595, 1875; Yarrow, Bull. U. S. Nat. Mus., 24, pp. 64, 189, 1883; idem, Smithson. Misc. Coll., 517, p. 11, 1883; Belding, W. Amer. Sci., 3, p. 98, 1887; Burt, Trans. Kans. Acad. Sci., 38, p. 275, 1936. Sceloporus rufidorsum Yarrow, Proc. U. S. Nat. Mus., 5, pp. 442-443, 1882 (part); idem, Bull. U. S. Nat. Mus., 24, p. 64, 1883; idem, Smithson. Misc. Coll., 517, p. 11, 1883; Garman, Bull. Essex Inst., 16, p. 18, 1884; Belding, W. Amer. Sci., 3, p. 96, 1887; idem, p. 98, 1887; Townsend, Proc. U. S. Nat. Mus., 13, p. 144, 1890. Sceloporus magister zosteromus Linsdale, Univ. Calif. Publ., Zool., 38, p. 366, 1932; Burt, Amer. Mid. Nat., 14, p. 237, 1933. 1939 MEXICAN LIZARDS SMITH 171 Type locality. Cape San Lucas, Lower California. Cotypes USNM 5298 (23), 69472-88. Distribution. Cape Region of Lower California (fig. 13). Diagnosis. A large Sceloporus, maximum snout-vent measure- ment 97.5 mm.; dorsal scales 26 to 32, average 29.3; ventral scales 36 to 46, average 41.3; scales around body 32 to 39, average 34.4; femoral pores 16 to 22, average 18.6; dorsal scales keeled, strongly mucronate; supraoculars six, rarely seven, the last two (seldom only the last) in contact with median head scales; outer row of labio- mentals usually in contact with mental; first canthal in contact with lorilabials; lateral scale rows with oblique, narrow, dark lines; a broad, light band down middle of back, not bordered laterally by a series of darker spots (except in young) ; shoulder patch with a light, posterior border; belly patches (males) separated, with a dark medial border. Variation. The variation in cephalic scutellation is practically identical with that of m. monserratensis, and need not be repeated. Dorsal scales 26 to 32, average 29.3 (83 counts: 26, one; 27, eight; 28, ten; 29, twenty-six; 30, twenty-one; 31, fifteen; 32, two); ventral scales 36 to 46, average 41.3 (24 counts: 36, one; 37, one; 38, one; 39, three; 40, two; 41, three; 42, five; 43, four; 44, three; 46, one); scales around body 32 to 39, average 34.4 (24 counts: 32, five; 33, four; 34, three; 35, six; 36, two; 37, three; 39, one). Femoral pores 16 to 22, average 18.6 (160 counts: 16, eleven; 17, thirty-six; 18, thirty-two; 19, forty; 20, twenty-one; 21, fifteen; 22, five). The only diagnostic difference between m. monserratensis and m. zoster omus is in color; in femoral pore counts there is a slight but insignificant difference. In the former, there is a narrow light median dorsal band bordered on either side by a series of dark spots or by a dark band; in m. zoster omus the dark spots and bands are missing (except in the very young) and the entire dorsal surface is occupied by a broad light band. The young of m. monserratensis and m. zosteromus seem to differ in color. In the latter, the markings on the back and sides are dis- tinct and the black shoulder spot is gray. In m. monserratensis the markings are very distinct, especially anteriorly, and the shoulder spots are very black. In the rather immature males (76 to 88 mm. snout to vent) the dorsal spots are absent, and in their stead are two irregular series, one on each side of the mid-dorsal line, of irregular pale blue spots. 172 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 In these the tail has no regular markings; the bases of the caudal scales are brownish, the outer part straw yellow. The ventral abdominal coloration of adult males is as in m. mon- serratensis, not as in ra. rufidorsum. Locality records. LOWER CALIFORNIA: Agua Caliente (UMMZ 56072; CAS 46745-55, 46788-9; MVZ 11729-32); Buenavista (CAS 46743-4); Cape San Lucas (USNM 5298, 69483-8, 15893, 37672; AMNH 5473; CAS 46768; LMK 2733, 10775-7); El Centenario, near La Paz (USNM 62718); El Triunfo (MVZ 13623-4); El Zacatal (MVZ 2); Eureka (MVZ 11733); San Antonio (4 mi. E of El Triunfo) (CAS 46741-2, 46829); Miraflores (USNM 69473-9, 64466-7; FMNH 25845; AMNH 5489, 5484; CAS 46756-8, 46792); San Jose" del Cabo (USNM 46889-90, 64468-71; FMNH 659; LSJU 2958-9, 2962-4; CAS 46759-67, 46793-9); San Jose Mission (USNM 69481- 2); San Pablo (Van Denburgh, 1895); San Pedro (MCZ 13183-4; CAS 46735-40, 46778); Santa Anita (USNM 37671; MVZ 11728); Santiago (USNM 69480, 69472); Todos Santos (CAS 46769-74, 46813^; MVZ 11712-25). THE UNDULATUS GROUP Thirteen forms are regarded as forming the undulatus group; nine are confined to areas north of the Mexican boundary, and only one to Mexico. The southern limit of distribution is central Zacate- cas. Only the four forms which enter Mexico are treated in the present paper, and these in abbreviated form since the group has recently been treated in a separate paper (Smith, 1938). KEY TO FORMS OF THE UNDULATUS GROUP 1. First canthal in contact with lorilabials woodi First canthal not in contact with lorilabials 2 2. Scales on posterior surface of thigh abruptly differentiated from dorsal scales of same member, median posterior scales not distinctly larger than adjacent lateral posterior scales 3 Scales on posterior surface of thigh gradually merging with larger dorsal scales of same member, at least the median posterior scales distinctly larger than the adjacent lateral posterior scales 6 3. Labial region, chin and throat crossed by irregular, diagonal, dark lines radiating from the gular region; frontoparietals often in contact with enlarged supraoculars o. becki Labial region, chin and throat not crossed by radiating dark and light lines or bands; frontoparietal plate very rarely in contact with enlarged supra- oculars 4 4. Blue belly patches not confluent with throat patches, and separated from each other by a lighter or darker midventral band 5 Blue belly patches confluent with throat patches, and not separated from each other by a lighter or darker midventral band; ventral surfaces deep blue throughout o. taylori 1939 MEXICAN LIZARDS SMITH 173 5. Blue of throat in males in paired lateral patches (blue widest laterally or separated by median white stripe) which may merge medially in older specimens; under parts very light in color or speckled with darker scales. o. occidentalis Blue of throat in males in a central patch, never divided; under parts often gray or black o. biseriatus (p. 174) 6. Femoral pore series separated by nine or more scales; gular patches discrete, widely separated cautus (p. 173) Femoral pore series separated by eight scales or less; or if nine or more the gular patches large and closely approximated and meeting, the whole throat frequently blue and black 7 7. Dorsal scales 37 or less 8 Dorsal scales 38 or more 9 8. Males lacking belly patches u. virgatus (p. 176) Males with broad, lateral belly patches u. undulatus 9. Dorsal scales 45 or more u. elongatus Dorsal scales 44 or less 10 10. Males without lateral belly patches; dorsolateral and lateral light stripes very distinct u. virgatus (p. 176) Males with lateral belly patches 11 11. Males without gular patches; femoral pores 14 or less; dorsolateral light stripes distinct in both sexes u. garmani Males with gular patches 12 12. Females with lateral belly patches; femoral pores 16 or more (74.7 per cent). u. tristichus Females without lateral belly patches 13 13. Dorsolateral light stripes distinct in males; dorsal crossbars reduced in males, confined to areas between dorsolateral light stripes; gular region with two dark patches posteriorly, not extending over entire throat; femoral pores 16 or more (69.7 per cent) u. consobrinus (p. 175) Dorsolateral light stripes indistinct in males; dorsal crossbars extending completely across back when visible; gular region almost entirely black in adult males; femoral pores 15 or less (80.7 per cent) u. fascialus Sceloporus cautus Smith. Sceloporus cautus Smith, Occ. Papers Mus. Zool. Univ. Mich., 387, p. 2, 1938. Type locality. Thirty miles north of El Salado (San Luis Potosi), in Coahuila. Type EHT 13027. Distribution. Eastern Zacatecas, northwestern San Luis Potosi, and extreme southern Coahuila. Diagnosis. A Sceloporus of the undulatus group, of relatively large size (maximum snout-vent measurement 80 mm.); scales on posterior surface of thigh somewhat smaller than preanal scales; dorsal scales 31 to 39; femoral pores 10 to 14, the two series separated medially by 9 to 12 scales; supraoculars large, entire, separated from median head scales by one complete series of scales, from super- ciliaries by one complete and one incomplete series of small scales; dorsal scales strongly mucronate; two dark spots on either side of throat posteriorly in both sexes; dorsolateral light stripes present, but broken or faint; back barred in females; males with a series of 174 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 dark spots on each side of mid-dorsal line; lateral belly marks blue, dark bordered, widely separated medially. Variation. There is surprisingly little variation in cephalic scutellation. In the 11 specimens examined the head scales are similar to those of the type except: five superciliaries in two; one incomplete and two complete rows of small scales between supra- oculars and superciliaries in one; six supraoculars in one; fifth supra- ocular narrowly in contact with median head scales in one; pre- f rentals separated by an azygous scale in five; internasals irregular in six; preocular entire on both sides in nine, on one side in one; two complete rows of lorilabials below subocular in six. Variation in body scale counts is given in the table accompanying the original description. Comparisons. If it is correct to assume that the undulatus group is derived from the spinosus group, cautus may be considered a "missing link" between the two groups. The species is obviously closely related to spinosus, but differs from it in characters which associate it with the undulatus group. From spinosus spinosus, cautus differs in the following characters: blue spots at posterolateral edge of throat (never in spinosus, in which the throat is barred) ; supraoculars five or six (usually four in spinosus spinosus) ; femoral pores 10 to 14 (rarely 11 or 12 in s. spino- sus); dorsal scales 31 to 39 (rarely more than 30 in s. spinosus); dorsal bands more numerous (nine or ten in cautus, six or seven in s. spinosus). From u. undulatus, which has an average dorsal scale count near that of cautus, the latter form differs in the ventral coloration of the male, in the character of the supraocular scales, number of scales between femoral pore series, character of the auricular lobules, and number of dorsal crossbars. S. occidentalis biseriatus differs in average dorsal scale count, average femoral pore count, character of supraocular scales, and ventral coloration. Locality records. COAHUILA: 30 mi. N of El Salado, San Luis Potosi (EHT 13027-8). SAN Luis Poxosf : Charcas (UMMZ 77274); 30 mi. N of Matehuala (EHT 13025). ZACATECAS: 10 mi. S of Majoma (EHT 13050, 13056-61). Sceloporus occidentalis biseriatus Hallowell. Sceloporus biseriatus Hallowell, Proc. Acad. Nat. Sci. Phila., 7, p. 93, 1854. Sceloporus occidentalis biseriatus Camp, Univ. Calif. Publ., Zool., 17, p. 65, 1916. 1939 MEXICAN LIZARDS SMITH 175 Type locality. El Paso Creek, Tejon Valley, California. Distribution. Southern Idaho, southwest through Nevada and western Utah into California; San Pedro Martir range in Lower California. Diagnosis. First canthal not in contact with lorilabials; scales on posterior surface of thigh abruptly differentiated from dorsal scales of same member, the median posterior scales not distinctly larger than adjacent lateral posterior scales; femoral pore series separated medially by nine or more scales; femoral pores 13 to 18; dorsal scales 35 to 44; throat not barred; belly patches in males not confluent with throat patch; a single central throat patch in males. Locality records. 1 - Lower California records are from Tiajuana, Laguna Hanson, San Antonio, Ensenada, Santo Tomas, Decarte, Valladares, San Pedro Martir Mountain, Trinidad, Santa Rosa, San Jose", Rosarito Divide, San Isidro Ranch, Nachoguero Valley near United States border, Sauz and San Ramon (Van Denburgh, 1922; Schmidt, 1922; Linsdale, 1932). Sceloporus undulatus consobrinus Baird and Girard. Sceloporus consobrinus Baird and Girard, in Marcy and McClellan, Explor. Red R., La., p. 237, pi. 10, figs. 5-12, 1853. Sceloporus undulatus consobrinus Cope, Ann. Rept. U. S. Nat. Mus., 1898, p. 377, fig. 60, 1900. Type locality. Red River, Beckham County, Oklahoma. Distribution. Texas except eastern fourth, southwestern Okla- homa, extreme western and southern fourth of New Mexico, south- eastern Arizona in vicinity of San Pedro River, south in Mexico to central Zacatecas, central Chihuahua on the west and central Tamaulipas on the east. Diagnosis.- First canthal not in contact with lorilabials; scales on posterior surface of thigh gradually merging with larger dorsals of same member, at least the median posterior scales distinctly larger than the adjacent lateral posterior scales; femoral pore series sepa- rated by eight scales or less; dorsal scales 35 to 47, average 40; males with lateral belly patches and distinct lateral gular patches; dorso- lateral light lines distinct in males, indistinct in females; females unmarked ventrally; femoral pores usually 16 or more (70 per cent). Locality records. 1 CHIHUAHUA: 10 mi. S of Moctezuma (EHT 13062) ; 10 mi. S of Chihuahua (EHT 13080) ; Rio San Pedro between Chihuahua and Naica (EHT 13034-5); 25 mi. S of Jimenez (EHT 1 United States records not listed. 176 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 13036-42); 10 mi. N of Escalon (EHT 13043-5). COAHUILA: 10 mi. E of Torreon (EHT 13029-30); 30 mi. N of El Salado (EHT 13026). DURANGO: 10 mi. S of Escalon (EHT 13046); Yermo (EHT 13047-8); 25 mi. N of Bermejillo (EHT 13049). NUEVO LE6N: Sabinas Hi- dalgo (EHT 13033); 31 mi. S of Sabinas Hidalgo (EHT 13031-2). ZACATECAS: La Colorada (EHT 13051-5, 13068). Sceloporus undulatus virgatus Smith. Sceloporus undulatus virgatus Smith, Occ. Papers Mus. Zool. Univ. Mich., 387, p. 11, 1938. Type locality. Above Santa Maria Mine, El Tigre Mountains, Sonora. Type UMMZ 81912, collected by Berry Campbell. Distribution. Huachuca and Chiricahua Mountains, in Arizona, and El Tigre Mountains in northeastern Sonora, at high elevations. Diagnosis. A small Sceloporus of the undulatus group, maximum snout-vent measurement about 62 mm.; dorsolateral and lateral light stripes very distinct, unbroken; dorsal dark spots small, fre- quently indistinct; a distinct, broad, dark band below dorsolateral light line; femoral pores 12 to 16; dorsal scales 36 to 42; femoral pore series separated medially by 4 to 7 scales; both sexes immaculate white on belly, with very small blue spots on throat posteriorly, one on each side. Locality records. ARIZONA: Chiricahua Mts. (UMMZ 71146-9 [5]) ; Montezuma Canyon, Huachuca Mts. (UMMZ 69911). SONORA: El Tigre Mts. (UMMZ 78417-21 [13], 81912). THE GRACIOSUS GROUP Three forms compose the graciosus group, only one of which is found in Mexico, in extreme northern Lower California. KEY TO FORMS OF THE GRACIOSUS GROUP 1. Dorsal scales usually 52 or less; dorsolateral light stripes usually very distinct. g. graciosus Dorsal scales 53 or more; dorsolateral light stripes usually indistinct or absent . 2 2. Adult males with ventrolateral blue patches separated by a whitish midventral area of considerable width; blue on under surface of body not confluent with blue of throat; females less dusky below g. gracilis Adult males with ventrolateral blue patches united across midventral line or separated by a narrow whitish interval ; blue or black of belly confluent with that of throat; under surface of tail and thighs often colored. g. vandenburgianus (p. 176) Sceloporus graciosus vandenburgianus Cope. Sceloporus vandenburgianus Cope, Amer. Nat., 30, p. 834, 1896. Sceloporus graciosus vandenburgianus Camp, Univ. Calif. Publ., Zool., 17, p. 67, 1916. 1939 MEXICAN LIZARDS SMITH 177 Type locality. Summit of the coast range, San Diego County, California. Distribution. Mountains south of Ventura County, California, south into Lower California. Diagnosis. Femoral pore series separated medially by 14 or more scales; the pore series not encroaching onto preanal region, separated from it by a few series of small scales; gular region mottled; never with one or two distinct, blue or black spots posteriorly; dorsal scales 53 or more; dorsolateral light stripes indistinct; adult males with ventrolateral blue patches united across midventral line or separated by a narrow whitish interval; blue or black of belly con- fluent with that of throat; under surface of tail and thighs often colored. Locality records. Specimens have been recorded from the San Pedro Martir Mountains in Lower California, at Agua de las Fresas, Vallecitos, and La Grulla. THE GRAMMICUS GROUP 1 Nine species have been described in the grammicus group: dispar Baird and Girard, disparilis Stejneger, grammicus Wiegmann, heterolepis Boulenger, heterurus Cope, microlepidotus Wiegmann, pilsbryi Dunn, pleurostictus Wiegmann, and rubrimntris Giinther. 2 Of these nine forms proposed I recognize four: grammicus, heterolepis, microlepidotus microlepidotus, and microlepidotus disparilis. The distribution of the group is compact but extensive, covering all of Mexico, except parts of the coastal regions, from central Chi- huahua and northern Coahuila south to the Isthmus of Tehuantepec. One form (m. disparilis} invades the southern tip of Texas. In scutellation the group shows little variation, except as regards the dorsal scales, which exhibit most of the specific and subspecific characters. S. heterolepis is most modified, the dorsal scales being highly irregular in size. In dorsal coloration the various members of the group show close relationship, all having a gray ground color, the back with zigzag, narrow lines across it, the lines sometimes broader medially. So far as is known, all forms are arboreal. All except m. disparilis live at rather high elevations. S. microlepidotus is ovoviviparous, and it is assumed that the other two species are also. 1 Approximately 989 specimens examined. 2 S. microlepidppterus Herrera, 1889, and S. microlepis Boulenger, 1894, are lapsi calami for microlepidotus. 178 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 S. grammicus is the connecting link between the grammicus and formosus groups. Its closest relative in the latter group is formosus smamgdinus, which has a remarkably similar dorsal color pattern and relatively small scales. The members of the formosus group also are arboreal and ovoviviparous. The structural characters which the members of this group have in common and by which they differ from other groups and species of DISPARILIS MICROLEPIDOTUS MEGALEPIDURUS HETEROLEPIS PICTUS FIG. 15. Phylogeny of the grammicus and megalepidurus groups. Sceloporus are: scales on posterior surface of thighs granular; dorsal scales 48 to 93 (as few as 37 in heterolepis, counting along one of the series of enlarged scales) ; moderately large size (maximum snout-vent measurement of largest species, 81 mm.; of smallest species, 64 mm.) ; no postfemoral dermal pocket; lateral scales in oblique rows; supra- oculars numerous, usually in two series; usually four postrostrals; preanals smooth in both sexes; males distinctively colored below; usually a dark blotch in front of arm insertion, with a short, narrow, dorsal extension; and back with several narrow, dark cross-lines. 1939 MEXICAN LIZARDS SMITH 179 KEY TO SPECIES AND SUBSPECIES OF THE GRAMMICUS GROUP 1. Dorsal scales unequal; a series of enlarged scales on each side of mid-dorsal line, separated from each other by small, flat scales. . . .heterole-pis (p. 197) Dorsal scales more or less uniform in size 2 2. Scales on sides of neck not abruptly differentiated from dorsal nuchal scales; no enlarged series of scales on sides of neck (see fig. 17, p. 185); dorsal scales 48 to 59 grammicus (p. 179) Scales on sides of neck abruptly differentiated from dorsal nuchal scales; two series of enlarged scales on sides of neck posterior to ear (see fig. 18, p. 197); dorsal scales 52 to 93 3 3. Dorsal scales usually less than 70 (52 to 74) m. disparilis (p. 191) Dorsal scales usually 70 or more (68 to 93) m. microlepidotus (p. 183) Sceloporus grammicus Wiegmann. Sceloporus grammicus Wiegmann, Isis, 21, p. 370, 1828; idem, Herp. Mex., p. 51, 1834; Gravenhorst, Nova Acta Acad. Leop., 18, pp. 767-768, 1837; Fitzinger, Syst. Kept., 1, p. 76, 1843; Baird and Girard, in Stansbury, Explor. Great Salt Lake, p. 344, 1852; Dumeril, Arch. Mus. Hist. Nat. Paris, 8, p. 547, 1856; Miiller, Reisen Ver. Staaten, Canada, Mex., 3, p. 602, 1865; Cope, Proc. Acad. Nat. Sci. Phila., 1866, p. 323, 1867; West- phal-Castelnau, Congr. Scient. France, 35, p. 285, 1872; Bocourt, Ann. Sci. Nat., Zool., (5), 17, No. 10, p. 2, 1873; idem, Miss. Sci. Mex., Zool., 3, sec. 1, pp. 192-194, pi. 18bis, figs. 12, 12 a, 12 b, 1874; Duges, Naturaleza, 4, p. 30, 1877; Cope, Proc. Amer. Phil. Soc., 22, pp. 395, 397, 1885 (part); Boulenger, Cat. Liz. Brit. Mus., 2, pp. 218, 231-232, 1885; Cope, Bull. U. S. Nat. Mus., 32, p. 36, 1887 (part); Duges, Naturaleza, (2), 1, p. 112, 1888; Giinther, Biol. Cent.-Amer., Rept. Batr., p. 71, 1890 (part); Herrera, Cat. Rept. Mus. Nac., Mexico, p. 18, 1895; Boulenger, Proc. Zool. Soc. Lond., 1897, pp. 476, 508-509, 1897 (part); Cope, Ann. Rept. U. S. Nat. Mus., 1898, pp. 335, 392-393, 1900; Herrera, Cat. Rept. Mus. Nac., Mexico, 2nd ed., p. 18, 1904; Smith, Trans. Kans. Acad. Sci., 37, p. 272, 1934. Sceloporus pleurostictus Wiegmann, Isis, 21, p. 370, 1828 "Mexico"; Duges, Naturaleza, (2), 1, p. 112, 1888. Tropidurus grammicus Wagler, Syst. Amph., p. 146, 1830. Tropidolepis pleurostictus Gray, in Cuvier, Animal Kingdom, Griffith ed., 10, [App.], p. 43, 1831; Lichtenstein, Nomen. Rept. Amph., p. 9, 1856. Tropidolepis grammicus Gray, in Cuvier, Animal Kingdom, Griffith ed., 10, [App.], p. 43, 1831; Dumeril and Bibron, Erp. Gen., 4, pp. 306-307, 1837; Gray, Cat. Liz. Brit. Mus., p. 209, 1845; Dumeril and Dumeril, Cat. M6th., p. 77, 1851; Lichtenstein, Nomen. Rept. Amph., p. 9, 1856; Jan, Cenni. Rept. Mus. Milano, p. 39, 1857. Type locality. Mexico. Distribution. Southern Oaxaca. 1 Diagnosis. A Sceloporus of moderate size, maximum snout-vent measurement approximately 67 mm.; scales on posterior surface of 1 Boulenger (1885, 1897), records this species from Guatemala. It is likely that his specimens should be referred to formosus smaragdinus. 180 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 thigh granular; no postfemoral dermal pocket; lateral scale rows oblique; lateral nuchal scales merging gradually with dorsal nuchal scales, not abruptly differentiated from the latter; enlarged postanals present in males; preanals smooth; sides of belly bluish in males; dorsal scales 48 to 59; ventral scales 55 to 57; scales around body 54 to 58; 12 to 15 dorsal scales in head length; femoral pores 13 to 16. Description. 1 Head scales smooth, slightly convex, pitted; a prefrontal depression visible, surrounded by weak ridges; inter- parietal rather irregular in shape, more or less pentagonal, two and one-half to three times as large as either parietal; parietal single on either side; a single, small frontoparietal on each side, separated medially by an azygous scale or by contact of frontal with inter- parietal; frontal typically divided; six or seven superciliaries in inner row; four or five smaller scales in outer row of superciliaries; one complete and another nearly complete row of small scales between supraoculars and superciliaries, and one complete row between supra- oculars and median head scales; six superciliaries, five visible from above; pref rentals separated by contact of frontal and median fron- tonasal; frontonasals typical; three pairs of internasals; subnasal present, divided into two on both sides in one, on one side in other (one side injured) ; two canthals, typical in position, the first some- what smaller than the second; preocular entire; one loreal on each side; four or five postrostrals; two or thre'e postoculars; two rows of lorilabial scales, complete below subocular; four supralabials and six or seven infralabials to a point below middle of eye. Mental subtriangular, with a labial border two-thirds to three- fourths that of rostral; four or five pairs of postmentals, the scales of the anterior pair in contact medially; anterior scale of outer row of labiomentals separated from mental by partial contact of first postmental and first infralabial ; gular scales smooth, weakly notched, except those below ear and near angle of jaws, which are keeled and pointed. Auricular lobules about four in number, very short, smooth, pointed, subequal in size to or slightly smaller than preceding scales; temporal scales keeled, weakly mucronate, the anterior scales smaller than posterior and subequal in size to median scales between ear and nuchal pocket; a loose skin fold extending obliquely upward from upper edge of nuchal pocket to a point above arm insertion; small axillary scales continuing immediately above arm insertion and for- ward into nuchal pocket, there becoming granular; dorsal nuchal 1 Based on USNM 30134-5, "Tehuantepec." 1939 MEXICAN LIZARDS SMITH 181 scales not well differentiated from lateral nuchal scales between ear and nuchal pocket; scales of lateral row of dorsals on neck not enlarged or strongly keeled, or otherwise differentiated from temporal or lateral nuchal scales. Dorsal body scales rather strongly keeled and mucronate, not denticulate, in convergent rows; median lateral scales two-thirds to three-fourths size of dorsal scales, in oblique rows; ventral scales FIG. 16. Lateral nuchal scales of Sceloporus grammicus. somewhat smaller than lateral scales, weakly notched or pointed; scales on chest distinctly larger than median ventral scales. Dorsal scales of foreleg similar to dorsals on body, except some- what smaller; scales on anterior surface of lower foreleg smooth, somewhat larger than other scales of same member; ventral scales of lower foreleg keeled, mucronate, denticulate; ventral scales of upper foreleg smooth, notched, one-third to one-half size of ventral scales of lower foreleg; the lamellar formula for the fingers 8-12- 16-18-13. Dorsal scales of hind legs similar in character to dorsal body scales, those on shank slightly smaller than dorsals on thigh and subequal in size to those on body; scales on ventral surfaces of thigh smooth, pointed, decreasing in size toward femoral pore series, increasing in size to anterior surface of thigh; scales on posterior surface of thigh very small, keeled, mucronate, about one-fifth or one-sixth size of 182 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 preanal scales; ventral scales on shank smooth, subequal in size to dorsal scales of same member; lamellar formula for toes 7-11-17-19- 15 (7-11-17-20-16). Dorsal caudal scales strongly keeled and mucronate, about one and one-half times as large as dorsals on body; basal subcaudals smooth and notched; subcaudals becoming pointed and keeled distally; enlarged postanals present; no postfemoral dermal pocket. Color. Dorsal surfaces dull greenish olive; sides of body darker, with scattered dark spots; gular region with faint bluish bars; chest bluish or white; sides of belly pale blue, bordered by a very narrow blue border; latter edged medially with a very narrow black line, the two lines closely approximated medially; none of the blue belly coloration extending into groin or onto preanal area; ventral surfaces of limbs and tail dusky white. A very narrow, black line extends up- ward from upper anterior edge of arm insertion a short distance onto sides of neck. The two specimens examined are so badly faded that it is almost impossible to make out the original pattern or coloration. The color description given by Bocourt (1874, pp. 193-194), who had examined Wiegmann's type, follows (in translation): "Superior regions of a metallic green, sometimes very brilliant, with several narrow, undulate, brown bands joining in chevrons on the middle of the back; the sides darker, showing numerous small, black brown and yellow spots. Below, the males have on the median part of the belly two parallel black bands, closely approximated to each other, each bordered laterally by blue. In some individuals, the gular region is traversed by black; this color extends considerably upon the articulation of the arm, passing upward on each side upon the scapula as a very narrow line, which is interrupted between the shoulders; throat frequently tinted with gray and with small, scat- tered, whitish dots." Comparisons. From m. microlepidotus, the present species differs most obviously in the size of the dorsal scales. From m. disparilis, the northern parallel of grammicus, the latter species differs in certain minor details of squamation : scales on sides of neck between ear and nuchal pocket larger, not sharply differentiated from dorsal nuchal scales (well differentiated in m. disparilis'), and pref rental depression distinct, surrounded by weak ridges (very indistinct or absent in m. disparilis). The dorsal scales may average larger (less numerous between occiput and base of tail) than in m. disparilis. 1939 MEXICAN LIZARDS SMITH 183 It is possible though not certain that two specimens of m. micro- lepidotus from "Tehuantepec" (USNM 30132-3) were collected with the two grammicus. These two are quite distinct from grammicus, with the typical m. microlepidotus coloration and 76-83 dorsal scales. Locality records. OAXACA: "Tehuantepec" (USNM 30134-5) (probably from the mountains near the middle of the isthmus); Oaxaca (Bocourt, 1874). Sceloporus microlepidotus microlepidotus Wiegmann. Sceloporus grammicus var. alpha Wiegmann, 21, Isis, p. 370, 1828. Sceloporus microlepidotus Wiegmann, Herp. Mex., p. 51, 1834; Fitzinger, Syst. Kept., 1, p. 76, 1843; Miiller, Reisen Ver. Staaten, Canada, Mex., 3, p. 602, 1865; Peters, Monatsber. Akad. Wiss. Berl., 1869, p. 874, 1869; Dumeril, Nouv. Arch. Mus. Hist. Nat. Paris, 5, pp. 48, 52, 1870; Sumi- chrast, Bibl. Univ. Rev. Suisse, 46, p. 243, 1873; Bocourt, Miss. Sci. Mex., Zool., 3, sec. 1, pp. 194-195, pi. 18bis, figs. 13, 13 a-d, 1874; Duges, Na- turaleza, 4, p. 30, 1877; Sumichrast, Naturaleza, 6, p. 38, 1882; Garman, Bull. Essex Inst., 16, p. 18, 1884; Cope, Proc. Amer. Phil. Soc., 22, p. 170, 1885; idem, 22, pp. 379, 384, 1885 (part); Boulenger, Cat. Liz. Brit. Mus., 2, pp. 218, 232-233, 1885 (part); Ferarri-Perez, Proc. U. S. Nat. Mus., 9, p. 193, 1886; Cope, Bull. U. S. Nat. Mus., 32, p. 36, 1887 (part); Garman, Bull. Essex Inst., 19, p. 132, 1887; Duges, Naturaleza, (2), 1, pp. 112-113, 1888; Gunther, Biol. Cent.-Amer., Rept. Batr., pp. 72-73, 1890 (part); Herrera, Naturaleza, (2), 2, pp. 65, 83, 1891; Ives, Proc. Acad. Nat. Sci. Phila., 1891, p. 462, 1892; Herrera, Naturaleza, (2), 2, pp. 330-345, 1893; Boettger, Kat. Rept. Senck. Mus., p. 65, 1893; Blatchley, Proc. U. S. Nat. Mus., 16, p. 41, 1893 (part); Herrera, Cat. Rept. Mus. Nac., Mexico, p. 18, 1895; Cope, Amer. Nat., 30, pp. 1021-1023, 1896; Duges, Naturaleza, (2). 2, p. 479, 1896; Cope, Ann. Rept. U. S. Nat. Mus., 1898, pp. 335, 340, 394, 1900 (part); Herrera, Cat. Rept. Mus. Nac., Mexico, 2nd ed., p. 18, 1904; Gadow, Proc. Zool. Soc. Lond., 2, pp. 195, 214, 230, 232, 1905; idem, Through Southern Mexico, pp. 57, 270, 271, 380, 511, 1908; idem, Zool. Jahr., Syst., 29, pp. 706, 713, 714, 1910; Stejneger, Proc. Biol. Soc. Wash., 29, pp. 227-230, 1916; Flower, Vert. Animals Zool. Soc. Lond., 3, p. 243, 1929; Gadow, Jorullo, pp. 50, 69, 1930; Mertens, Abh. Ber. Mus. Naturk. u. Naturw. Ver. Magdeburg, 6, p. 158, 1930; Martin del Campo, Anales Inst. Biol. Mexico, 7, p. 275, 1936; Hesse, Allee, and Schmidt, Ecol. Animal Geogr., p. 501, 1937. Tropidolepis microlepidotus Dumeril and Bibron, Erp. Gen., 4, p. 308, 1837; Gray, Cat. Liz. Brit. Mus., p. 209, 1845; Dumeril and Dumeril, Cat. Meth., p. 77, 1851; Lichtenstein, Nomen. Rept. Amph., p. 9, 1856; Jan, Cenni Rept. Mus. Milano, p. 39, 1857; Duges, Naturaleza, 1, p. 143, 1870. Uta microlepidota Baird and Girard, in Stansbury, Explor. Great Salt Lake, pp. 344-345, 1852; Dumeril, Arch. Mus. Hist. Nat. Paris, 8, p. 548, 1856. Sceloporus dispar Baird and Girard, Proc. Acad. Nat. Sci. Phila., 6, p. 127, 1852 Vera Cruz; Dumeril, Arch. Mus. Hist. Nat. Paris, 8, p. 547, 1856; 184 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 Miiller, Reisen Ver. Staaten, Canada, Mex., 3, p. 602, 1865; Duges, Natu- raleza, 4, p. 30, 1877. Sceloporus heterurus Cope, Proc. Acad. Nat. Sci. Phila., 1866, pp. 322-323, 1867 Mirador, Vera Cruz. Tropidolepis grammicus Duges, Naturaleza, 1, p. 143, 1870. Tropidolepis microlepidus Westphal-Castelnau, Congr. Scient. France, 35, p. 285, 1872. Sceloporus grammicus Cope, Proc. Amer. Phil. Soc., 18, p. 265, 1879; idem, 22, pp. 395, 397, 1885 (part); idem, Bull. U. S. Nat. Mus., 32, p. 36, 1887 (part); Gunther, Biol. Cent. Amer. Kept. Batr., p. 71, 1890 (part); Duges, Naturaleza, (2), 2, p. 479, 1896; Boulenger, Proc. Zool. Soc. Lond., 1897, pp. 508-509, 1897 (part). Sceloporus microlepidopterus Herrera, Naturaleza, (2), 1, p. 331, 1890 (lapsus calami). Sceloporus rubriventris Gunther, Biol. Cent.-Amer., Kept. Batr., p. 72, pi. 32, fig. C, 1890 Omilteme, Guerrero; Boulenger, Proc. Zool. Soc. Lond., 1890, p. 78, 1890; Cope, Amer. Nat., 30, p. 1024, 1896; Dunn, Proc. Acad. Nat. Sci. Phila., 88, p. 474, 1936. Sceloporus microlepis Boulenger, Proc. Zool. Soc. Lond., 1894, p. 731, 1894 (lapsus calami). Type locality. Mexico. Distribution. Southern part of Mexican Plateau, from Jalisco, northern Guanajuato, and northern Hidalgo, to central Oaxaca (fig. 18) . Diagnosis. A Sceloporus of moderate size, maximum snout-vent measurement 81 mm.; scales on posterior surface of thighs granular; no postfemoral dermal pocket; lateral scale rows oblique; lateral nuchal scales abruptly differentiated from dorsal nuchal scales; the scales of the lateral row of dorsal nuchals somewhat enlarged, more strongly keeled than others; dorsal scales 68 to 93, average 77.9; scales around body 60 to 85, average 72.2; ventral scales 51 to 73, average 61.6; femoral pores 13 to 22, average 17; frontoparietals usually single on each side; pref rentals usually in contact; two rows of lorilabials, one usually incomplete; males with enlarged postanals; preanals smooth; dorsal color gray; several crossbars, usually narrow, on back; sides of belly bluish in males. Description. 1 Head scales smooth, somewhat convex, strongly pitted; interparietal very large, about four times as large as either parietal, about three-fifths size of supraorbital area; one parietal on each side, small; frontoparietals usually one, frequently two, on each side; frontal generally in contact with interparietal; the two sections of frontal seldom subdivided; supraoculars in two rows, the scales of the outer row about one-third or one-fourth size of scales in 1 Based chiefly on UMMZ 55758, female, San Juan Teotihuacan. 1939 MEXICAN LIZARDS SMITH 185 inner row; usually about seven or eight scales in the inner row of supraoculars; two irregular rows of scales between supraoculars and superciliaries; six superciliaries, five visible from above (rarely five or seven superciliaries) ; one row of scales, rarely incomplete, between supraoculars and median head scales; pref rentals mostly in contact medially, frequently separated by contact of frontal and median frontonasal, or by an azygous scale; internasals more or less irregular, usually in two pairs; subnasal present; two canthals, generally one FIG. 17. Lateral nuchal scales of Sceloporus microlepidotus microlepidotus, loreal; preocular usually entire; usually four postrostrals; two rows of lorilabials, frequently reduced to one row below subocular by one or more scales in contact with both subocular and supralabials; two postoculars; four supralabials and five infralabials to a point below middle of eye. Mental pentagonal, with a labial border about two-thirds that of rostral; outer row of labiomentals narrowly separated from mental by partial contact of first postmental and first infralabial; about six pairs of postmentals, the scales of only the anterior pair in contact medially; gular scales notched (except anterior scales), the notches difficult to discern or absent in young specimens; gular scales more strongly notched toward sides of throat. 186 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 Auricular lobules short, smooth, pointed, not extending across ear opening, subequal in size to preceding scales (sometimes slightly larger or smaller) ; temporal scales keeled, not or weakly mucronate, not denticulate, the median and lower scales smallest, the largest somewhat larger than scales between ear and lateral nuchal pocket; scales immediately behind ear granular, sharply increasing in size posteriorly and ventrally; a fold, surmounted by somewhat enlarged, strongly keeled scales, extending from middle of nuchal pocket to lower edge of ear; another fold, without differentiated scales, passing obliquely upward a short distance onto back, originating at extreme posterodorsal edge of nuchal fold; scales between lower part of nuchal fold and the fold extending to lower edge of ear weakly keeled, mucronate, weakly denticulate; scales between nuchal pocket and arm granular dorsally, much larger and notched ventrally; lateral nuchal scales between ear and nuchal pocket strongly differentiated from dorsal nuchal scales; scales in lateral row of dorsal nuchals strongly keeled, well differentiated from other dorsal nuchal scales, the row abruptly terminating at a point above and slightly posterior to posterior margin of ear. Dorsal scales keeled, weakly mucronate, weakly (although distinctly) denticulate (the denticulations are not visible on scales whose original epidermal covering is lost) ; lateral abdominal scales not well differentiated from dorsals, more strongly mucronate and denticulate; ventral scales subequal in size to lateral scales, smooth, notched. Dorsal scales of foreleg weakly keeled, weakly mucronate; scales at elbow denticulate or notched; dorsal scales of lower foreleg sub- equal in size to dorsal scales on body, those on upper foreleg slightly larger; posteroventral scales of lower foreleg keeled, usually with two apical notches; anteroventral scales of lower foreleg smooth, with a single apical notch; ventral scales of upper foreleg weakly keeled (anteriorly) or smooth (posteriorly), about one-third size of ventral scales of lower foreleg; lamellar formula for fingers 10-7-20- 20-14 (9-15-19-21-16). Dorsal scales of hind leg about one and one-third times as large as dorsals on body, keeled and mucronate, not or weakly denticulate; scales on anterior surfaces of thigh smooth, notched, the scales becoming smaller on ventral surface toward femoral pore series; scales on posterior surface of thigh very small (granular in young specimens), much smaller than preanal scales, the largest ones (in a central area and adjacent to femoral pore series) keeled, mucronate; 1939 MEXICAN LIZARDS SMITH 187 scales on ventral surface of shank smooth, rounded or weakly notched, slightly smaller than dorsal scales of same member; lamellar formula for toes 7-14-18-25-18 (9-14-19-23-17). Dorsal caudal scales about three (sometimes four) times as large as dorsal body scales, keeled, moderately strongly mucronate; basal subcaudals smooth, rounded or weakly notched in males, becoming keeled, mucronate and weakly denticulate toward tip of tail; basal subcaudals weakly keeled toward sides of tail in females, and some- what mucronate; enlarged postanals present in males; no postfemoral dermal pocket. Color. Dorsal surface in males dark gray, gray-brown, olive- gray, bright olive or light yellowish-brown; in specimens in which the head is marked, a brown lighter band across prefrontal area, bordered posteriorly by a distinct narrow black line; snout dark gray; frequently a W-shaped, narrow, black mark across fronto- parietal area (head frequently uniform brownish or gray, without markings); a narrow black nuchal collar (occasionally absent, notably in central Vera Cruz specimens from very high altitudes), broken medially by a space about six scales wide; the collar may be bordered posteriorly by a distinct narrow white line; a black line extending from posterior edge of orbit across upper edge of ear opening to nuchal collar; this is sometimes bordered above by a narrow white line; a black shoulder patch usually present (absent in specimens from region about Tehuacan, Puebla) ; the upper part of the area between ear and nuchal pocket may or may not be entirely or partially black (generally black in Vera Cruz specimens) ; on each side of back a series of about six narrow black lines, each extending forward, then turning posteriorly near middle of back; the lines on one side may alternate or coincide in position with the lines on the opposite side; in some specimens a faint indistinctly outlined dorsolateral light stripe is present; the sides of the abdomen are marked with numerous dark lines, usually narrow, sometimes parallel with the body axis, sometimes oblique; the sides may be mottled, or with series of dark spots sometimes arranged in longi- tudinal rows; in some specimens the undulate marks on the back extend onto the sides of the abdomen. Ventral surfaces extremely variable in coloration; usually the chin and infralabial regions are dark, the central part of the throat lighter (perhaps pinkish or lavender in life); the chest is mottled with black; the sides of the abdomen are cyanine blue, bordered medially on each side by a narrow black area not extending across 188 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 chest nor into groin; the black borders are separated from each other by a narrow dusky area; ventral surfaces of limbs and tail dusky; tail faintly barred below. A variant of this ventral coloration occurs in the Sierra Madre Oriental. In these the sides of the gular area are cream, the median gular area pale blue; the gular fold region and anterior part of chest are black, the color continuous with that of a broad median ventral band which expands into the groin and preanal areas and onto the ventral surfaces of the thigh. In certain specimens the whole gular area is pale blue, the gular fold region black, the chest dusky, the ventral surfaces of the limbs and tail pale blue. Specimens from the area about Tehuacan, Puebla, are very light in ventral coloration; the median gular area and sides of abdomen are china blue or slightly darker; the infralabial region, chest, and sides of abdomen lateral to the blue patches are stippled lightly with black; the ventral surfaces of the limbs are cream or bluish. Females are similar to males in general features of the dorsal coloration and markings, except that the color is less brilliant and the dark markings more distinct. Females from the region about Tehuacan have the sides of the abdomen uniform, except for the undulate bars which extend down from the back, and are nearly immaculate below; the labiomental region is faintly stippled. The ventral surfaces are more or less uniform cream or bluish, except the throat, which is usually heavily stippled with black; light-colored scales are scattered over the throat; generally two fairly distinct, parallel dark lines are present near the middle of the throat; the anterior part of the chest may be lightly mottled. Variation. The variation in the scutellation of the head in 115 specimens has been recorded. Parietals one to four (1, four; 2, one hundred and seventy-one; 3, fifty- three; four, one); frontoparietals one to three on each side (1, one hundred and seventy-eight; 2, forty- three; 3, five) ; frontal in contact with interparietal in 97, separated by an azygous scale in 12, by contact of frontoparietals in five; anterior section of frontal variously divided in seven ;superciliaries five to seven (5, twelve; 6, two hundred and one; 7, seventeen); three to eight scales in outer row of supraoculars, usually five; supraoculars (inner row) five to ten (5, four; 6, thirty-three; 7, one hundred and fifteen; 8, forty-five; 9, twenty-two; 10, one); one or more supraoculars contact median head scales in six; pref rentals in contact medially in 62, separated by an azygous scale in 27, by contact of frontal 1939 MEXICAN LIZARDS SMITH 189 and median frontonasal in 25; median frontonasal separated from lateral frontonasals in one; internasals rather irregular; subnasal present in all; canthals one to three (1, nine; 2, two hundred and nine- teen ; 3, two) ; first canthal forced above canthal ridge on both sides in 14, on one side in seven; first canthal in contact with lorilabials in two; loreals none to three (none, thirteen; 1, two hundred and one; 2, eleven; 3, five); postrostrals two to six (2, three; 3, eight; 4, ninety-six; 5, seven; 6, one); lorilabials reduced to one row below subocular by one or more scales in contact with both subocular and supralabials on one side in 20, on both sides in 77. Dorsal scales 68 to 93, average 77.9 (226 counts: 68, five; 69, four; 70, six; 71, six; 72, twenty-one; 73, ten; 74, fifteen; 75, fifteen; 76, eighteen; 77, twenty; 78, eleven; 79, fifteen; 80, fifteen; 81, seven; 82, ten; 83, twelve; 84, seven; 85, nine; 86, six; 87, four; 88, five; 89, two; 90, one; 93, two). Ventral scales 51 to 73, average 61.6 (127 counts: 51, one; 53, three; 54, two; 56, four; 57, six; 58, ten; 59, thirteen; 60, eleven; 61, thirteen; 62, thirteen; 63, ten; 64, nine; 65, eleven; 66, eight; 67, four; 68, three; 69, one; 70, three; 72, one; 73, one). Scales around body 60 to 85, average 72.2 (129 counts: 60, one; 62, two; 63, one; 64, three; 65, three; 66, four; 67, four; 68, nine; 69, twelve; 70, nine; 71, eleven; 72, fifteen; 73, six; 74, ten; 75, twelve; 76, six; 77, three; 78, five; 79, six; 80, one; 82, two; 83, two; 84, one; 85, one). Femoral pores 13 to 22, average 17 (243 counts: 13, one; 14, six; 15, thirty; 16, fifty-eight; 17, fifty- seven; 18, fifty-two; 19, twenty-seven, 20, seven; 21, four; 22, one). Two specimens from Cerro de San Luis, north of Oaxaca, are exceptional in having the dorsal scale count 61, 63. Specimens from parts of Guerrero and Oaxaca have a lower average dorsal count than the average for the whole subspecies, but do not differ sufficiently to warrant recognition. Specimens from Vera Cruz have a higher average than others; the highest counts for the subspecies occur in this area. This subspecies tends strongly toward formation of local popula- tions which differ from each other in various minor characters such as details of coloration, average dorsal scale count, and size of supra- oculars; the populations are not, so far as I can determine, sufficiently well marked to be differentiated from other populations. The population areas which seem best defined are: Vera Cruz, western and northern Puebla; Guerrero and central Oaxaca; valley of Mexico northward over the southern half of the Mexican plateau, including the inward slopes of adjacent mountain ranges. 190 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 The dorsal scale count 70 has arbitrarily been assumed as the point of division between m. microlepidotus and m. disparilis. Nine out of 226 m. microlepidotus are under this count (4 per cent), and three out of 127 m. disparilis are over this count (2.4 per cent). Using this character alone, 3.4 per cent of the total number of speci- mens counted of both subspecies are confused. Habits and habitat. The subspecies is completely arboreal, as is its relative m. disparilis. In many places it is exceedingly common. Specimens are observed most frequently in open woods where plenty of sunlight is available. In the early hours of the morning and on cool days they are frequently found under bark. Specimens have been recorded from elevations of 13,500 feet on Mount Orizaba, and 11,200 feet on Mount Ixtaccihuatl. As recorded by Herrera, Gadow, and. others, m. microlepidotus is ovoviviparous. Schmidt (Hesse, Allee, and Schmidt, 1937, p. 501) states that "on Mount Orizaba in southern Mexico, the iguanid lizard, Sceloporus microlepidotus, is oviparous at the base and vivi- parous at high levels, the eggs at intermediate levels doubtless under- going part of their development in the mother's body." He believes this statement to be derived from Gadow; but he and I together have been unable to find the source for this statement in the literature. Locality records. COLIMA: (Bocourt, 1874). DISTRITO FEDERAL: Mexico City (CAS 73470; USNM 18990-6, 81922; ANSP 11721, 11444-5; MCZ 4528[2], 4530[2], 16428); Chapultepec (ANSP 8516); Tacubaya (MCZ 6733[3]); Coyoacan (MCZ 4778); 1 mi. W of Los Remedios (AMNH 15489); 2 mi. W of Tacuba (AMNH 15491, 15532-8) ; 2 mi. S of San Miguel Peak, Ajusco Range (AMNH 17984- 5); San Juanico (AMNH 15594, 15598, 15571-81); N of Guadelupe (AMNH 15606); ruins of El Desierto (AMNH 15548-51, 15555-70); Tlalpam (FMNH 17097); Tlamacas (Herrera, 1893); La Cruz (Herrera, 1893); Xochimilco (Gadow, 1905); Contreras (Gadow, 1905). GUANAJUATO: (USNM 12685); 3 mi. NE of Santa Rosa (EHT 9819-21); Santa Rosa (USNM 47784-6); Tupataro (USNM 10236); San Diego de la Union (USNM 46875-6). GUERRERO: Tamazulapam (USNM 47600); Mts. near Chilpancingo (USNM 47601-3); Chilpancingo (MCZ 33905); Iguala (Gadow, 1905); Omilteme (Gadow, 1905). HIDALGO: Yolotepec (WM 1); 55 mi. N of Mexico City (EHT 9540-4); Tulancingo (USNM 47374-7, 46775- 6); Marques (USNM 47523); Pachuca (USNM 47772-3, 47293-5); Zacualtipan (USNM 14746, 16023-4, 16026); Velasco (UMMZ 71441); La Mora (Martin del Campo, 1936); Canguihuindo (Mar- 1939 MEXICAN LIZARDS SMITH 191 tin del Campo, 1936). JALISCO: Nevado de Colima (Gadow, 1905). MEXICO: Amecameca (WM 1; FMNH 1300 [24]); San Juan Teoti- huacan (CAS 54633-4; USNM 19015; MCZ 6339 [19]; UMMZ 55758[6]); Lumbrera (MVZ 8861, 8867-9); El Tajo de Tequixquiac (MVZ 8854-60, 8862-5); Lerma (EHT 9750, 9822); 2 mi. S of San Martin (EHT 9823-6); 35-40 mi. E of Mexico City (EHT 9652-5); Nevado de Toluca (EHT 9686-7); Popocatepetl (USNM 47281-5; MCZ 16076-87); Valley of Mexico and Toluca (USNM 32288); Valley of Mexico (USNM 2953[16]; MCZ 33906-10); Salazar (USNM 47296, 46896); San Andres (ANSP 8521); Ixtaccihuatl (ANSP 8517); Toluca (ANSP 12562); Zumpango (AMNH 15539); Zacatal (AMNH 14222-3); Chalco (FMNH 1002 [14], 1278 [23]); Texcoco Lake (FMNH 1004[9]). MICHOACAN: 15 mi. SE of Zitacuaro -r ^ . (EHT 9749); Uruapan (EHT 9559-9637, 9833-5). MORELOS: Tres Marias (EHT 9757-77, 9689-9700); 5-6 km. S of Tres Marias (EHT 9778-9, 9545-8); 9-14 km. S of Tres Marias (EHT 9780-92, 9549-58, 9701-7); Zempoala (EHT 9638-51, 9683-5); 40 leagues S of Mexico City (USNM 2950); Cuautla (FMNH 17098, 1280[7], 1304[3]); Cuernavaca (FMNH 17099). OAXACA: Cerro de San Luis, N of Oaxaca (EHT 9836-7); "Tehuantepec" (USNM 30132-3); Mts. near Ozolotepec (USNM 47846); Reyes (USNM 47369); Cerro San Felipe (USNM 47388-90); Valley of Miahuatlan (AMNH 17977). PUEBLA: (MCZ 9553); Canada de Morelos (EHT 9744); Tehuacan (WM 2); Rio Frio (EHT 9745-8, 9797-9818); 20 km. N of Tehuacan (EHT 9655A, 9656-63); 15 mi. E of San Marcos (EHT 9708); Teziutlan (MCZ 7472; FMNH 1341[20]); Mt. Orizaba (USNM 4787-8, 47290, 47767-8; FMNH 1518[15]); Chalchicomula (USNM 19022-8; MCZ 16438-40); Atlixco (USNM 47036; FMNH 1302[3]); Huauchinango (USNM 47822-8); Santa Catarina (AMNH 18514, 18516-7, 18746-7, 18750-2) ; Puebla (FMNH 1323[9]; AMNH 18497-500, 18777-89; FMNH 1003[2], 1324[20]); Cholula (AMNH 18486-96); Tochimilco (USNM 46777); Tlapanala (Izucar de Matamoros) (Ferrari Perez, 1886). VERA CRUZ: (?)Tierra Colorada (EHT 9709, 9793); Cruz Blanca (EHT 9710-3, 9794-6, 9664-80); Jico (USNM 47372); Cofre de Perote (USNM 47381-6); Mt. Orizaba (USNM 47615-26, 19020-1; ANSP 8518-20); Maltrata (USNM 19009-11); Orizaba (USNM 30191^); Mirador (USNM 25064); Xuchil (USNM 58691-2; FMNH 1520[9]); Jalapa (Cope, 1885). Sceloporus microlepidotus disparilis Stejneger. Sceloporus dispar Bailey, N. Amer. Fauna, 25, p. 42, 1905; Strecker, Baylor Bull., 18, No. 4, p. 21, 1915; Stejneger, Proc. Biol. Soc. Wash., 29, p. 227, 1916. 192 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 Sceloporus microlepidotus Boulenger, Cat. Liz. Brit. Mus., 2, pp. 218, 232-233, 1885 (part); Gunther, Biol. Cent.-Amer., Kept. Amph., pp. 72-73, 1890 (part); Cope, Ann. Kept. U. S. Nat. Mus., 1898, p. 394, 1900; Mosauer, Herpetologica, 1, p. 5, 1936. Sceloporus ornatus Boulenger, Proc. Zool. Soc. Lond., 1890, p. 78, 1890; Gun- ther, Biol. Cent.-Amer., Kept. Amph., p. 72, 1890; Boulenger, Proc. Zool. Soc. Lond., 1897, pp. 485-486, 1897. Sceloporus grammicus Cope, Proc. Amer. Phil. Soc., 23, pp. 283, 287, 1886; Carman, Bull. Essex Inst., 19, p. 132, 1887; Cope, Bull. U. S. Nat. Mus., 32, p. 36, 1887 (part); idem, Ann. Kept. U. S. Nat. Mus., 1898, pp. 335, 392-393, 1900 (part). Sceloporus disparilis Stejneger, Proc. Biol. Soc. Wash., 29, pp. 227-230, 1916; Stejneger and Barbour, Cheek List N. Amer. Amph. Kept., p. 53, 1917; idem, 2nd ed., p. 55, 1923; idem, 3rd ed., pp. 60-61, 1933; Burt, Trans. Kans. Acad. Sci., 38, pp. 276, 278, 299, 305, 1936; Mulaik, Copeia, 1936, p. 72, 1936; Gaige, Univ. Mich. Stud., Sci., 12, pp. 301-304, 1937; Burt, Papers Mich. Acad. Sci., 22, pp. 534, 535, 1937. Sceloporus microlepidotus disparilis Dunn, Proc. Acad. Nat. Sci. Phila., 88, p. 472, 1936. Sceloporus microlepidotus microlepidotus Dunn, Proc. Acad. Nat. Sci. Phila., 88, pp. 472-473, 474, 1936. Sceloporus pilsbryi Dunn, Proc. Acad. Nat. Sci. Phila., 88, pp. 473-474, 1936 Alvarez, San Luis Potosf type ANSP 20085. Type locality. Lomita Ranch, six miles north of Hidalgo, Texas. Type USNM 33041, collected by William Lloyd. Distribution. Northern Hidalgo and Guanajuato and southern Zacatecas northward to central Chihuahua and northern Coahuila; in Nuevo Leon and Tamaulipas to the southern tip of Texas (fig. 18). Diagnosis. A Sceloporus of moderate size, maximum snout-vent measurement 71 mm.; scales on posterior surface of thighs granular; no postfemoral dermal pocket; lateral scale rows oblique; lateral nuchal scales abruptly differentiated from dorsal nuchal scales; the scales of the lateral row of dorsal nuchals somewhat enlarged, more strongly keeled than others; dorsal scales 52 to 74, average 62; scales around body 50 to 71, average 61.5; ventral scales 49 to 65, average 58.3; femoral pores 12 to 20, average 15.4; frontoparietals usually divided on each side; pref rentals usually separated; usually two complete rows of lorilabials; males with enlarged postanals; preanals smooth; dorsal color gray; several crossbars on back, usually narrow; belly bluish in males. Description of type. 1 "Adult male. Head-shields smooth; two canthal scales, between the posterior of which three larger [fronto- nasal] shields cross the snout; frontal shield divided transversely; 1 From Stejneger, Proc. Biol. Soc. Wash., 29, pp. 228-229, 1916. 1939 MEXICAN LIZARDS SMITH 193 posterior frontal broadly in contact with interparietal ; interparietal very large, much broader than long and fused with the parietals; five large transverse supraorbitals separated from the frontals and interparietal by a single series of scales and from the superciliaries by a double row of scales; six supralabials separated from the nasals and from the long subocular by a single row of scales; fifth supralabial under the center of the eye; anterior border of the ear opening pro- tected by about five, small, slightly projecting scales; dorsal scales about the same size as ventrals, rounded behind, distinctly keeled, forming slightly oblia.ue longitudinal series converging toward the median line back of the shoulders; about 65 scales along the middle line of the back from the shielded part of the head to the base of the tail ; 17 scales in the middle of the back corresponding to the shielded part of the head; lateral scales directed upward and backward, scarcely different in size from the dorsals; ventral scales smooth, rounded behind, entire; scales on throat distinctly smaller than ventrals; adpressed hind limb reaches the anterior border of the ear; tibia slightly shorter than the shielded part of the head; the distance between the base of the fifth toe and extremity of the fourth exceeds by a half millimeter the distance between the end of the snout and the ear; 16-17 femoral pores; caudal scales much larger than dorsals, the keels ending in a point beyond the posterior border of the scales; two enlarged postanals." Color. Ground color (in females from Texas) light gray; two narrow parallel black lines, one on either side of mid-dorsal line, extending from anterior part of nape a varying distance onto the back (never farther than middle of back); a narrow black line ex- tending laterally and slightly anteriorly from the nuchal lines at a point approximately even with axilla to a point in front of arm insertion, there joining another narrow black line extending pos- teriorly onto proximal part of foreleg; a narrow black line extending from posterior margin of orbit through upper edge of ear to a point above arm insertion, there joining the line extending laterally; a narrow black line curving upward and posteriorly from extreme posterior upper margin of orbit, sometimes reaching the longitudinal nuchal lines, sometimes terminating on upper part of temporal region; a series of four or five narrow black undulate bars on each side of back, those of the two sides coinciding in relative position or not; each transverse bar on back expanded near mid-dorsal line; sides of body not or somewhat mottled with black; lower foreleg with very distinct narrow black bars; hind leg irregularly barred; 194 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 tail with narrow black bars separated from each other by about three scales; posterior surface of thighs reticulated with black and gray; head with numerous narrow black lines, the most constant of which are: a vertical line below orbit; anterior to this a line extend- ing obliquely forward from orbit to supralabials; a line on or below canthus; a line across frontonasals; one across anterior section of frontal. A few black flecks on throat and sides of abdomen; venter otherwise immaculate, whitish. Adult males (in Texas) lose almost all trace of the dorsal mark- ings; the only distinct dorsal mark is the nearly vertical one in front of arm, extending to mid-dorsal region; it is expanded somewhat in front of arm insertion. Throat finely mottled or stippled with black; central region of throat usually flesh color, sometimes pale blue; a narrow or broad black line across gular fold region, present or not; sides of belly pale blue (appears flesh color in preserved specimens), bordered medially by a short, narrow, black border; chest somewhat mottled in some specimens; remainder of ventral surfaces whitish. The variation in coloration of specimens from Texas is relatively little, although males have been observed which have the belly and throat colored in a highly variable fashion. The general charac- teristics of Texas specimens are the very distinct markings in the females and the reduction of the amount of mottling on the sides of the body. Males from Mexico show a highly variable ventral coloration, and both sexes have the sides of the body somewhat mottled, al- though usually not so strongly mottled as in typical m. micro- lepidotus. In males as small as 41 mm. from snout to vent, the gular black collar is complete ventrally; the throat varies enormously in coloration, even in juvenile specimens; in some the throat is heavily mottled and stippled with black, with a few minute light blue spots scattered over its surface; in others the stippling is con- fined to the labial regions; in some the median part of the throat is pale blue, in others pink; in older specimens the black median ventral borders may be united, extending across the chest and joining with the gular collar. So far as I can determine there is little cor- relation of these color variants with size, and as all phases occur in a single restricted area, I have not attempted to segregate more than one species or subspecies. Variation. The variation of the head scales in 83 specimens is as follows: parietals one to three (1, five; 2, one hundred and sixteen; 3, f orty-f our) ; frontoparietals one to three (1, sixty-eight; 2, seventy- 1939 MEXICAN LIZARDS SMITH 195 five; 3, twenty); frontal touches parietal in 61, separated by an azygous scale in 13, by contact of frontoparietals in eight; posterior section of frontal transversely divided in one; anterior section of frontal variously divided in nine; superciliaries four to seven (4, one; five, four; 6, one hundred and forty-nine; 7, twelve); none to seven scales in outer row of supraoculars, usually four or five; supraoculars four to eight (4, seven; 5, sixty; 6, seventy-six; 7, twenty; 8, one); prefrontals contact medially in 14, separated by an azygous scale in 33, by contact of frontal and median frontonasal in 37; usually two or three regular pairs of internasals, the scales frequently irregular; subnasal present in all; canthals one to three (1, six; 2, one hundred and fifty-nine; 3, one); first canthal forced above canthal ridge on both sides in two, on one side in four; first canthal in contact with lorilabials on one side in two; preocular divided on both sides in 20, on one side in 8; loreals none to three (none, one; 1, one hundred and thirty-six; 2, twenty-four; 3, five) ; postrostrals two to five (2, six; 3, ten; 4, sixty-five; 5, two); lorilabials reduced to one row below subocular by contact of one or more scales with both subocular and supralabials on one side in 15, on both sides in 20. Dorsal scales 52 to 74, average 62 (127 counts: 52, one; 55, two; 56, six; 57, six; 58, six; 59, nine; 60, fourteen; 61, fifteen; 62, fifteen; 63, fourteen; 64, eleven; 65, nine; 66, four; 67, three; 68, five; 69, four; 71, one; 72, one; 74, one). Ventral scales 49 to 65, average 58.3 (93 counts: 49, one; 51, one; 52, three; 54, seven; 55, five; 56, seven; 57, eleven; 58, eleven; 59, ten; 60, ten; 61, eight; 62, six; 63, nine; 64, two; 65, two). Scales around body 50 to 71, average 61.5 (101 counts: 50, one; 52, one; 53, one; 54, four; 55, two; 56, five; 57, five; 58, six; 59, eleven; 60, seven; 61, eight; 62, four; 63, fourteen; 64, eight; 65, four; 66, six; 67, six; 68, three; 70, two; 71, three). Femoral pores twelve to twenty, average 15.4 (175 counts: 12, one; 13, twelve; 14, thirty-six; 15, fifty-one; 16, thirty-nine; 17, twenty; 18, five; 19, nine; 20, two). Remarks. Sceloporus pilsbryi Dunn was based upon an adult male of ra. disparilis with a' broad gular collar and certain other features of ventral coloration not found frequently in the subspecies. The large supraoculars mentioned in the description occur occasion- ally in this form; they are not large, however, in comparison with the supraoculars of members of the spinosus or poinsettii group. The type is obviously identical with other Mexican m. disparilis. It is of importance to note that the dorsal scales were inadvertently recorded as 49, in the original description; the count actually is 59. 196 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 Habits and habitat. So far as known, these lizards are confined to an arboreal habitat. In southern Texas, where Dr. Taylor and I found them to be abundant, they are restricted to mesquite trees. They are exceedingly wary and at best difficult to distinguish from the similarly colored bark. As we found it difficult to collect them alone, we searched for them together with success. As it is their habit to retreat to the side of the tree opposite to that upon which one approaches, one of us would station himself on one side of the tree within gunshot of any possible lizards, while the other would beat the trunk and limbs on the opposite side, scaring the lizards to the side upon which they could be seen and shot. In central Nuevo Leon and northern San Luis Potosi, the species is fairly abundant in yuccas, trees being absent. In heavily wooded regions they are found on the larger trees. Mulaik (1936, p. 72) gives an interesting account of their life history. He finds that disparilis is ovoviviparous. Locality records. TEXAS: CAMERON co.: Brownsville (MCZ 13828). DUVAL CO.: (Boulenger, 1897). HIDALGO CO.: Mercedes (CM 388); 4 mi. S of Alamos (UMMZ 74745); Ojo de Agua (UMMZ 74792); Edinburg (UMMZ 79533, 79534[2], 79442; USNM 95865); Lomita Ranch, 6 mi. N of Hidalgo (USNM 33041-5). STARR CO.: Near Los Olmos Bridge, Rio Grande City (MCZ 33551-3; KU 15081; EHT 9853-66) ; Arroyo El Salado (KU 11000-4); Rio Grande City (KU 14945-8). CHIHUAHUA: (USNM 8311); Sierra Madre near Colonia Garcia (ANSP 15365; USNM 26610, 26598, 47255-6; BYU 2030-2); Samachique (FMNH 25942); Pacheco (MCZ 15607-9; Madera (MCZ 17531-4); Meadow Valley (USNM 26611); Sierra Madre (USNM 47542-5). COAHUILA: Sierra Guadelupe, S of El Cuchillo (ANSP 20128; USNM 46701); Del Carmen Mts. (FMNH 25307-9); Buenavista (USNM 2746); Carneros (USNM 46870); 30 mi. N of El Salado, San Luis Potosi (EHT 9753). DURANGO: Ciudad (Bou- lenger, 1885); Ventanas (Boulenger, 1885). GUANAJUATO: San Felipe (EHT 9751-2, 9829-32). HIDALGO: Cuesta Colorada, 10 km. N of Jacala (EHT 9531-5); La Placita, 8 km. S of Jacala (EHT 9536-7); Minas Viajas (EHT 9538-9); Durango (EHT 9681-2, 9688); Jacala (WM 2). NUEVO LE6N: Pablillo (ANSP 20121-2); 3 mi. W of Sabinas Hidalgo (EHT 9839, 9850-2, 9867-72). SAN Luis PoTOSf : Alvarez (ANSP 20085; UMMZ 67689[5]; MCZ 20047- 58, 20060-1; SDSNH 16309); Charcas (UMMZ 77284[41, 77285[8], 77286(5], 77287[12], 77288[2]); Moctezuma (UMMZ 77283); Sierra 1939 MEXICAN LIZARDS SMITH 197 de San Miguelito, about 30 mi. S of San Luis Potosi (MCZ 5432, 5433[6]); Mts. near San Luis Potosi (USNM 47160); 15 mi. S of Valles (EHT 9755-6); Coronado (EHT 9754, 9828); between El Salado and San Miguel (EHT 9839); Villa de Guadelupe (EHT 9827). TAMAULIPAS: Miquihuana (USNM 46736-8); Tamaulipeca (UMMZ 69238[13], 69239[9], 69240(10], 69241-2); Mier (USNM 47711). ZACATECAS: Plateado (USNM 46627, 46631-3); 10 mi. S of Majoma (EHT 9840-9). 1 Sceloporus heterolepis Boulenger. Sceloporus heterolepis Boulenger, Proc. Zool. Soc. Lond., 1894, pp. 724, 731, pi. 48, fig. 4, 1894; Cope, Amer. Nat., 30, p. 1024, 1896; Boulenger, Proc. Zool. Soc. Lond., 1897, pp. 476, 511-512, 1897; Gadow, Proc. Zool. Soc. Lond., 2, p. 232, 1905; idem, Jorullo, p. 49, 1930. FIG. 18. Distribution of the forms of the grammicus group: Sceloporus hetero- lepis, G; S. microlepidotus microlepidotus, O; S. m. disparilis, A. Type locality. State of Jalisco (La Cumbre de los Arrastrados, Real Alto, Riocho La Berberia, Sierra de Bolanos). One cotype in MCZ (No. 32346) ; other cotypes in British Museum. Distribution. Known only from Jalisco (fig. 18). 1 UMMZ 71445 is a disparilis. It is said to be from Matagalpa, Nicaragua, evidently erroneously. 198 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 Diagnosis. A Sceloporus of moderate size, of the grammicus group (maximum snout-vent measurement, 64 mm.); dorsal scales highly irregular in size and carination; two irregular series of en- larged, keeled scales on either side of mid-dorsal line, separated from each other by smaller scales. Description.* Head scales somewhat rugose; frontal ridges distinct, not sharp; interparietal very large, about four times as large as either parietal; frontal broadly in contact with interparietal and median frontonasal; supraoculars 5-6, separated from median head scales by a series of very narrow, small scales; one supraocular touches posterior section of frontal on one side; two supraoculars on each side with a small lateral section split off; supraoculars separated from superciliaries by one series of small scales; internasals irregular; two canthals, the first forced above canthal ridge by contact of second canthal and subnasal; subnasal and loreal large; one row of lorilabials on either side; lorilabials and labials smooth; preocular entire. Outer row of labiomentals short, separated from mental by con- tact of first and part of second infralabials with postmentals; scales of the first pair of postmentals in contact medially; gular scales weakly notched. Auricular lobules very short, smaller than scales preceding; some of temporal scales relatively very large; an oblique series of long, projecting scales below ear; a series of similar scales behind ear; scales immediately posterior to ear relatively small; a longitudinal series of enlarged scales behind and above ear, extending to a point above arm. A series of enlarged, keeled scales on each side of mid-dorsal line, beginning at occiput, converging at middle of neck (here separated by about one or two rows of small scales), diverging on back and becoming indistinguishable posteriorly; scales from occiput to base of tail 37 to 71, partly smooth, partly keeled, none mucronate; ventral scales smaller in general than those on back, notched, not larger than preanals. Scales on posterior surface of thigh slightly smaller than preanal scales; dorsal caudal scales larger than smaller scales on back, some- what irregular toward base of tail, more regular distally; lamellae on fourth toe 20-21; femoral pores 16-16; postanal scales enlarged in males; no postfemoral dermal pocket. 1 Based on MCZ 32346, La Cumbre de los Arrastrados. 1939 MEXICAN LIZARDS SMITH 199 Color. General ground color light gray; numerous, undulate dark marks on head, one of the two most conspicuous passing across orbits, the other across canthal and frontonasal region; a very narrow, dark brown scapular collar, divided medially, similar to that in microlepidotus; about four faint, brown, undulate bars passing across back; tail with distinct, complete bars; limbs with very faint, broad bars above. Throat with irregular dark marks; a light, immaculate white median band two scales wide, extending from middle of throat through to upper third of abdomen; sides of belly pale blue, bordered medially by dark blue, which does not pass onto chest; ventral surfaces of limbs with faint irregular dark marks. Variation. USNM 64665 compares well with the MCZ cotype, except that the two canthals are normal, and there are two complete rows of lorilabials; two postrostrals are present. Femoral pores 14 to 19, average 16.8 (30 counts: 14, two; 15, three; 16, ten; 17, eleven; 18, three; 19, one). Habits and habitat. Boulenger (1894) states that the species occurs at altitudes between 7,800 and 8,500 feet. Locality records. La Cumbre de los Arrastrados (MCZ 32346); La Laguna (USNM 64665); Real Alto, Riocho La Berberia, Sierra de Bolafios (Boulenger, 1894, p. 731). THE MEGALEPIDURUS GROUP 1 Two species are grouped together as a distinct section, the mega- lepidurus group. These are S. megalepidurus and pictus. The characters common to these species are: dorsal scales relatively small (44 to 62 from occiput to base of tail); lateral scales but slightly smaller than dorsal scales; lateral scales in oblique rows; scales on posterior surface of thigh nearly as large as preanal scales; ven- tral scales smooth, notched; no postfemoral dermal pocket; preanal scales smooth; subcaudal scales keeled except at base of tail; four postrostrals; head scales smooth; frontal with a single, transverse suture; two rows of enlarged supraoculars; usually one canthal, rarely two; scales on sides of neck not greatly reduced in size, except in a narrow area between arm and nuchal pocket; enlarged postanals distinct in males; lineate pattern; small size (maximum snout- vent measurement 54.3 mm.). The megalepidurus group is apparently most closely related to the grammicus group. It differs greatly in color pattern, and in size of scales on sides of neck and on the posterior surface of thigh. 1 Specimens examined, 136. 200 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 S. pictus, having larger scales than megalepidurus and a belly coloration typical for the genus in the males, is considered the more primitive of the two species (see diagrammatic representation of phylogeny). KEY TO SPECIES OF THE MEGALEPIDURUS GROUP Dorsal scales 44 to 56; scales between femoral pore series two to five; basal subcaudals keeled in females; males with distinct blue areas on sides of belly. picius (p. 200) Dorsal scales 54 to 62; scales between series of femoral pores four to eight; basal subcaudals smooth in females; males immaculate below. megalepidurus (p. 199) Sceloporus pictus Smith. Sceloporus consobrinus Boulenger, Cat. Liz. Brit. Mus., 2, pp. 229-230, 1885 (part); Gunther, Biol. Cent.-Amer., Rept. Batr., pp. 69, 70, 1890 (part); Boulenger, Proc. Zool. Soc. Lend., 1897, pp. 486-488, 1897 (part). Sceloporus pictus Smith, Amer. Mus. Nov., No. 892, pp. 1-4, 1936. FIG. 19. Distribution of Sceloporus megalepidurus, Q; and S, pictus, A. Type locality. Santa Catarina, Puebla. Type AMNH 18744, male, collected by Paul D. R. Ruthling. Distribution. Central western Vera Cruz and central Puebla. Diagnosis. A Sceloporus of small size, maximum snout-vent measurement approximately 55 mm.; dorsal scales 44 to 56 from 1939 MEXICAN LIZARDS SMITH 201 occiput to base of tail, average 49.6; lateral scales in oblique rows converging dorsally; scales around middle of body 45 to 53, average 49.1; femoral pores 13 to 20, average 16.6, the two series separated by two to five scales, average 3.5; usually one, rarely two canthals; frontoparietals usually entire; auricular lobules three to five, the upper lobule usually longest; caudal scales about twice as large as median dorsal scales on body; subcaudals keeled except near base of tail, more strongly keeled in females than in males; preanal scales smooth; ventral abdominal scales about half as large as median dorsal scales on body; no postfemoral dermal pocket. General dorsal color gray-olive or brown-olive; a broken, clove-brown band on each side of the body, bordered above and below by a narrow light line; limbs narrowly banded; a dark spot in front of shoulder; males with dark blue areas on sides of belly, black-bordered medially. Description of type. Head scales smooth, weakly pitted; inter- parietal large, longer than broad, broader posteriorly than anteriorly, its posterior edge rounded; a single parietal on each side, one-fourth or one-fifth size of interparietal ; a moderately large scale posterior to parietal which might be considered a secondary parietal, but which appears to be two nuchal scales fused together; a pair of very small, rectangular frontoparietals, separated medially by broad contact of the frontal and interparietal; frontal transversely divided, the posterior section two-thirds as large as anterior section; prefrontals moderate in size; separated medially by contact of frontal and median frontonasal; latter scale somewhat larger than either lateral frontonasal; a pair of narrow scales in front of median frontonasals, preceded by another similar pair of scales; five enlarged supraoculars on each side, the median scale divided on one side; two anterior supra- oculars abnormally in contact with median head scales on each side; other supraoculars separated from median head scales by a row of small scales; one complete and another incomplete row of scales separating supraoculars from superciliaries; six superciliaries on each side, normal; one canthal on each side; subnasal present, larger than loreal; preocular not divided; subocular long, single, followed pos- teriorly around margin of orbit by two keeled postoculars; two incomplete rows of lorilabials, reduced to one row below subocular; one row of lorilabials continuous around end of snout; three and one- half or four supralabials to a point below middle of eye. Mental pentagonal, with a labial border about half that of rostral ; outer row of labiomentals separated from mental by narrow contact of first postmen tal and first infralabial; three pairs of well- 202 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 differentiated postmentals, followed by several scales not well dif- ferentiated from adjoining gular scales; first pair of postmentals in contact medially; most of gular scales with a single apical notch; gular scales all nearly equal in size, somewhat smaller than scales on breast, smallest below ear and between postmentals. Auricular lobules three-four, the upper scale on one side con- siderably larger than the others (apparently injured early in life on the other side); about six scales between auricular lobules and postoculars; temporal scales keeled, immucronate, larger than scales between ear and lateral nuchal fold, smaller than largest auricular lobule; scales between ear and lateral nuchal fold keeled, mucronate; a series of keeled, mucronate scales passing from near upper edge of nuchal fold to below middle of ear. Dorsal scales not reduced in size on nape, weakly keeled, weakly mucronate, their free edges nearly straight, not rounded; lateral scales about one-third smaller than dorsals, not abruptly differenti- ated from them, more strongly keeled and mucronate than dorsals; all ventral scales except some on midventral line with a single apical notch; scales in axilla and groin imbricated, notched; scales on chest slightly larger than midventral scales; preanal scales somewhat smaller than lateral abdominal scales, subequal in size to smallest midventral scales; dorsal scales on rump somewhat reduced; dorsal caudal scales at least twice as large as scales on rump. Dorsal scales of upper foreleg keeled, mucronate, subequal in size to dorsal scales on body, slightly larger than largest dorsals on lower foreleg; scales on ventral surface of upper foreleg very small, notched, smooth, those of lower foreleg somewhat larger, weakly keeled, weakly mucronate; lamellar formula for fingers 8-13-18-18- 12 (8-12-17-17-11). Dorsal scales of shank subequal to median dorsals those of thigh slightly smaller; scales on anterodorsal surface of shank near tibio- metatarsal joint greatly reduced in size; ventral scales of shank notched, smooth, smaller than dorsal scales of same member; scales on anterior surface of thigh smooth, notched, somewhat smaller than dorsal scales of same member, decreasing in size on ventral surface near femoral pores; scales preceding femoral pores subequal to pre- anal scales; median scales on posterior surface of thigh keeled, mucro- nate, subequal to scales in preanal region, decreasing toward series of femoral pores; no postfemoral dermal pocket; enlarged postanals present, broader than long, separated narrowly by two small scales; lamellar formula for toes 8-13-18-19-14 (8-11-16-20-14). 1939 MEXICAN LIZARDS SMITH 203 Color. Dorsal surface olive-gray or brown-gray; a narrow light line from upper posterior margin of orbit along sides of body to rump, its medial edge not well defined, the lateral edge distinct; area between these lines without marks; below the lateral light line a broad, broken, clove-brown band, bordered below by a narrow light band from axilla to groin; below this, irregular scattered spots of clove-brown, absent toward ventral surface; a narrow white line through ear near upper edge, from upper labial region to upper margin of insertion of foreleg, bordered below on neck by a broad clove-brown band passing through lateral nuchal fold and becoming intense black on shoulder; limbs with narrow clove-brown bands; posterior surface of thigh irregularly reticulated with clove-brown. Males with throat blue, spotted or with narrow convergent lines of white; chest, middle of belly, and ventral surfaces of limbs whitish in young males, with a bluish suffusion in large males; sides of ab- domen cyanine blue, bordered medially by a narrow line of black; groin black; base of tail and a narrow line down the middle of the ventral surface of the tail whitish, usually with a bluish suffusion. Females occasionally uniform white or cream below, usually with a suffusion of blue over entire ventral surface, darker on throat, which has small white spots or narrow white bands. Dorsal surfaces as in the males, except a narrow dark line down each side of back. Variation. The variation in scutellation of the head has been examined in 21 specimens. Parietal single, with one to four, usually two, scales behind it; frontoparietals one or two (1, thirty-six; 2, four); frontoparietals in contact medially in none, separated by an azygous scale in two; frontal in contact with interparietals in 17; superciliaries six or seven (6, twenty-six; 7, four); supraoculars four to seven (4, six; 5, twenty; 6, eleven; 7, two); two supraoculars contact median head scales on one side in one; prefrontals in contact in 11, separated by an azygous scale in two; median frontonasal in contact with frontal in eight; nasal contacts rostral in one; inter- nasals usually two pairs; two canthals in two, the second in contact with subnasal on one side in one; preocular divided on one side in one, on both sides in one; two loreals on one side in one; three postrostrals in one, four in others; two complete rows of lorilabials below sub- ocular on one side in four, on both sides in one. Dorsal scales 44 to 56, average 49.6 (20 counts: 44, one; 45, two; 46, one; 47, two; 48, two; 49, two; 50, three; 51, one; 52, one; 53, two; 55, two; 56, one); ventral scales 48 to 57, average 51.4 (19 counts: 48, three; 49, three; 50, three; 51, one; 52, two; 53, three; 54, 204 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 one; 55, one; 56, one; 57, one); scales around body 45 to 53, average 49.1 (19 counts: 45, one; 46, one; 47, four; 48, four; 50, three; 51, three; 52, one; 53, two). Femoral pores 13 to 20, average 16.6 (13, two; 14, three; 15, two; 16, nine; 17, thirteen; 18, six; 19, one; 20, two). Scales between femoral pore series two to five, average 3.5 (2, two; 3, five; 4, seven; 5, one). Comparisons. The only species of Sceloporus to which pictus is closely related is megalepidurus, from which it differs by possessing fewer scales from occiput to base of tail (44 to 56 in pictus, 54 to 62 in megalepidurus); average of femoral pores greater (13 to 20, av. 16.6, in pictus; 13 to 18, av. 15.6 in megalepidurus); scales between series of femoral pores average fewer (two to five in pictus, four to eight in megalepidurus); basal subcaudals more strongly keeled (strongly keeled in females of pictus, smooth except near distal end of tail in megalepidurus); dorsal caudal scales proportionately larger; dorsal scales of shank smaller (subequal in size to median dorsal scales in pictus, larger in megalepidurus); fewer frontoparietals (usually one on each side in pictus, usually two or more in mega- lepidurus) ; no markings on the back in males (a double series of dark spots down the back in megalepidurus); males with distinct blue areas on sides of belly (uniformly whitish or with a general suffusion of pale blue in megalepidurus). Habits and habitat. Taylor has observed the species in Puebla and Vera Cruz, and states that it is confined to maguey plants. The individuals are extremely wary and difficult to extract from the thorny plants. Apparently semiarid localities are preferred. Locality records. VERA CRUZ: Acultzingo (EHT 7623, 7629A). PUEBLA: near Alseseca (EHT 7620A, 7620-2); 20 km. N of Tehuacan (EHT 7624-5, 7625A, 7626-9); Tehuacan (AMNH 42140-1); Santa Catarina (AMNH 18744-5, 18748-9, 18510-1, 18513, 18518); (?)Putla (Boulenger, 1885). Sceloporus megalepidurus Smith. Sceloporus microlepidotus Blatchley, Proc. U. S. Nat. Mus., 16, p. 41, 1893 (part). Sceloporus megalepidurus Smith, Trans. Kans. Acad. Sci., 37, pp. 272, 274-277, pi. 9, figs. 7, 8, pi. 10, fig. 13, 1934; idem, Herpetologica, 1, p. 4, 1936. Type locality. Totalco, Vera Cruz. Type EHT 7543, collected by E. H. Taylor and H. M. Smith. Distribution. Western Vera Cruz and northern Puebla (fig. 19). Diagnosis. A small Sceloporus, maximum snout-vent measure- ment about 55 mm.; head shields smooth; dorsal scales 54 to 62, 1939 MEXICAN LIZARDS SMITH 205 average 57.5; lateral scales in oblique rows converging dorsally; scales around body 48 to 57, average 52.7; femoral pores 13 to 18, average 15.6, the two series separated medially by four to eight scales, average 6.2; one canthal; frontoparietals usually divided; generally three auricular lobules, the upper largest; subcaudals smooth except toward tip of tail; preanal scales smooth; ventral abdominal scales somewhat smaller than dorsal scales on body; dorsal scales of shank usually larger than dorsal scales on body; no FIG. 20. Head scales of Sceloporus megalepidurus. postfemoral dermal pocket. Dorsal ground color seal brown; a dorsolateral light line, bordered below by a darker band, which in turn is edged below by a light band; a series of small dark spots on each side of middle of back, each spot bordered posteriorly by a larger light spot (invisible in specimens in which scales are shed); males and females immaculate below. Description. Cephalic scales smooth; dorsal scales on head, sides of neck and labial region pitted about edges; interparietal very large, about three or four times as large as either parietal; parietal followed posteriorly by one to four small scales, usually two; one to three frontoparietals, usually two, on each side; frontal transversely divided, rarely with additional divisions; frontal usually in contact with interparietal, frequently separated by contact of frontoparie- tals; supraoculars four to six, usually five; a row of small scales separating supraoculars from median head scales, rarely incomplete; supraoculars divided, the outer sections smaller than inner; one 206 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 complete and another incomplete row of small scales between supra- oculars and superciliaries; latter usually six, sometimes seven, five generally visible from above; prefrontals usually in contact; com- monly two pairs of internasals, occasionally three pairs, or one or two pairs followed by three scales, or, rarely, irregular; four post- rostrals; one can thai; one loreal; subnasal subequal in size to canthal; preocular rarely divided; the lorilabials usually reduced to one row below subocular by contact of one scale with subocular and supra- labials; two postoculars; three and one-half or four supralabials and five or six infralabials to a point below middle of eye. Mental pentagonal, broader than long, with a labial border about two-thirds that of rostral; about four pairs of postmentals, the scales of the anterior pair in contact medially; outer row of labiomentals separated from mental by partial contact of first postmental and first infralabial; median and posterior gular scales notched; largest^ gular scales near angle of jaws. Auricular lobules three, smooth, rounded or weakly pointed, the upper the largest and extending usually almost completely across tympanum; temporal scales weakly keeled, not mucronate except near ear, the largest subequal in size to or somewhat smaller than scales between ear and lateral nuchal pocket; latter scales nearly or quite as large as dorsal body scales, strongly keeled and mucronate; a weak fold passing from near middle of lateral nuchal fold to lower edge of ear, surmounted by scales more strongly keeled and mucron- ate than those surrounding; scales between arm and nuchal pocket variable in size, the upper and lower ones somewhat smaller than dorsal body scales, the median ones much smaller. Dorsal scales keeled, mucronate, sometimes weakly denticulate, in parallel or slightly convergent rows; lateral scales more strongly keeled, mucronate and denticulate than dorsal scales, the upper lateral scales slightly larger than dorsals, the median laterals slightly smaller; ventral scales slightly smaller than median lateral scales, smooth, notched; preanal scales smaller than ventral abdominals. Dorsal scales of foreleg of about equal size and about size of dorsals, keeled, mucronate, denticulate; ventral scales of lower foreleg somewhat smaller than dorsal scales of same member, the ante- roventral scales smooth, the posteroventral scales keeled; scales on ventral surface of upper foreleg smooth, notched, about one-third or one-fourth size of ventrals on lower foreleg; lamellar formula for fingers 8-14-17-18-11 (8-13-16-17-11). 1939 MEXICAN LIZARDS SMITH 207 Dorsal scales on thigh and shank strongly keeled, tridentate, somewhat larger than those on body, those on tibia largest; scales on anterior and ventral surfaces of thigh smooth, the ventral scales about one-half or one-third size of anterior scales; scales immediately preceding femoral pore series subequal in size to preanal scales; scales on posterior surface of thigh keeled, weakly mucronate, slightly smaller than preanal scales; ventral scales on shank smooth, notched or denticulate, subequal in size to or somewhat larger than dorsal scales of same member; lamellar formula for toes 9-13-17-20- 14 (9-12-18-20-14). Dorsal caudal scales one and one-half to two times as large as dorsal body scales, strongly keeled, mucronate, weakly denticulate; subcaudals smooth and notched at base of tail, becoming keeled, mucronate and denticulate distally; females with the subcaudals keeled nearer base of tail; enlarged postanals present and distinct in males; no postfemoral dermal pocket. Color, Approximately seal brown above; a dorsolateral light line extending from posterior corner of eye to base of tail, its inner border indistinct, the outer border distinct; between these lines, a series of 12 or 13 small black spots in a series on each side of median dorsal line, each spot usually bordered posteriorly by an indefinitely outlined small light spot; a clove-brown dark band below dorso- lateral light line, the band darkest on sides of neck, frequently split longitudinally on sides of body by an indistinct lighter line; a light line passing through labial region, through upper edge of ear to a point above arm, there uniting with a vertical line passing from insertion of foreleg to the dorsolateral light line; a light line below lateral dark band on sides of body between axilla and groin, bordered below by a clove-brown band becoming lighter toward venter; limbs with distinct dark narrow bars; tail with numerous narrow alternat- ing dark and light bands. Venter white or, more frequently, suffused with blue; a few, small light spots on throat. Variation. The variation of cephalic scutellation of 50 specimens has been recorded. Parietal single, with one to four, usually two, scales behind it; frontoparietals one to three on each side (1, thirty- two; 2, sixty-four; 3, four); frontoparietals in contact medially in 17, separated by an azygous scale in eight; frontal touches interparietal in 25; anterior section of frontal longitudinally divided in three, divided transversely in two, divided into three scales in two; posterior section of frontal transversely divided in one; superciliaries five to 208 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 seven (5, four; 6, ninety-one; 7, five) ; supraoculars four to six (4, eight ; 5, seventy-nine; 6, thirteen); supraoculars partially in contact with median head scales in eight specimens; prefrontals in contact medially in 30, separated by an azygous scale in 10; median fronto- nasal in contact with frontal in 10; usually two pairs of internasals; canthals one-one in all (94 specimens examined) ; preocular divided on one side in four, on both sides in six; two loreals on one side in one; three postrostrals in one, five in two, six in one (four in others); lorilabials reduced to one row below subocular by a scale in contact with both subocular and supralabials on one side in seven, on both sides in 39. Dorsal scales 54 to 62, average 57.5 (50 counts: 54, three; 55, four; 56, ten; 57, eleven; 58, four; 59, nine; 60, five; 61, three; 62, one); ventral scales 48 to 57, average 52.7 (50 counts: 48, two; 49, three; 50, five; 51, four; 52, eleven; 53, four; 54, eight; 55, seven; 56, four; 57, two); scales around body 49 to 58, average 53 (50 counts: 49, five; 50, three; 51, three; 52, seven; 53, eleven; 54, eleven; 55, two; 56, six; 57, one; 58, one). Femoral pores 13 to 18, average 15.6 (100 counts: 13, two; 14, eleven; 15, thirty; 16, forty; 17, four- teen; 18, three). Scales between series of femoral pores 4 to 8, average 6.2 (50 counts: 4, three; 5, seven; 6, nineteen; 7, eighteen; 8, three). Comparisons. The species is compared with pictus, its closest relative, in the discussion of the latter. Two species, described by Cope (heterurus) and Baird and Girard (dispar), require discrimina- tion. S. heterurus cannot be megalepidurus, since Cope (1866, p. 322) states that the type measures 2.5 inches snout to vent; the largest specimen examined of megalepidurus measures two and one-eighth inches snout to vent; he further states that there are "numerous delicate brown lines, directed obliquely forward toward the back and there turning backwards" a pattern found in neither megalepidurus nor pictus. S. dispar Baird and Girard (1854, p. 127) cannot be involved, as the male is stated to have the sides of the belly blue (eliminating megalepidurus); the "scales of the abdomen are likewise a little larger than those on the back"; in pictus the ventral abdominal scales are about one-half the size of the dorsal body scales. Habits and habitat. These lizards have been collected in the rather high, semiarid regions near the eastern edge of the Mexican plateau. They were largely confined to the ground on hills and lava beds, apparently not living on the plains. They were frequently 1939 MEXICAN LIZARDS SMITH 209 found under fallen yuccas. Most were caught by hand. Blatchley collected specimens at altitudes as high as 10,000 feet on Mount Orizaba. Locality records. PUEBLA: Volcan Orizaba (FMNH 1518[3]); Tepeyahualco (EHT 7500-10); 15 mi. E of San Marcos (EHT 7511- 41). VERA CRUZ: Totalco (EHT 7542-62, 7565-7610); Mt. Orizaba (MCZ 14157). THE POINSETTII GROUP Twenty species and subspecies allied to poinsettii have been described. Of these I recognize eighteen as valid. Distributional data indicate that the group is very definitely of Mexican origin. It is found in the United States only along the Mexican border, and in Central America only in the Pete"n region of Guatemala. Species of the group are as a rule confined to rocky habitats. So far as I am aware, only cyanogenys tends to live on or near the ground. S. jarrovii and serrifer are found on trees, jarrovii occasion- / Immucronatus Melonogaster S N Binocularis \ Supraoculars^ , one row \Lineolaterolis\ Formosus Plioporus ^-~-~ ^ - ^Supraoculars Serrifer ^- one row Spinosus FlG. 21. Phylogeny of the poinsettii group. 210 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 26 ally and serrifer perhaps usually. Individuals of most species are extremely wary and difficult to collect. In central Mexico a number of species are found in great abundance on rock fences. Full descriptions, synonymies, and lists of specimens of all forms of the group (save two, subsequently described) may be found in the Kansas University Science Bulletin, 21, pp. 539-693. Additional locality records are included here. KEY TO THE SPECIES AND SUBSPECIES OF THE POINSETTII GROUP 1. Supraoculars in a single series, with no scale divided 2 Supraoculars in two series; or, if in one series, with one or more scales divided 9 2. Femoral pores 8 to 14; dorsal scales 25 to 35 3 Femoral pores more than 14; or dorsal scales more than 35 5 3. Dorsal nuchal collar broadly interrupted medially by a space about five scales wide; throat mottled ferrariperezi binocularis (p. 216) Dorsal nuchal collar broad, complete; throat not mottled 4 4. Femoral pore counts on both sides usually total more than 21; dorsal scales usually 31 or more serrifer plioporus (p. 212) Femoral pore counts on both sides usually total less than 22; dorsal scales generally less than 31 serrifer serrifer (p. 212) 5. Dorsal scales 31 or less 6 Dorsal scales more than 31 7 6. Nuchal collar divided on each side of neck, the area between lighter in color; dorsal color light, with dark and light spots irregularly placed; size large (maximum snout- vent measurement 129 mm.); dorsal scales more strongly keeled and mucronate ferrariperezi melanogaster (p. 216) Nuchal collar broad, complete; dorsal color dark, without light spots; maxi- mum snout- vent measurement 98 mm.; dorsal scales more weakly keeled and mucronate ferrariperezi ferrariperezi (p. 214) 7.- Lateral scales about one-half as large as median dorsals. lineolateralis (p. 225) Lateral scales as large as or larger than dorsals 8 8. Dorsal scales 40 or more; nuchal collar narrow, with light borders broken; a light line on side of head and another on side of neck; each dorsal scale usually with a light median spot jarrovii jarrovii (p. 226) Dorsal scales usually less than 40; nuchal collar broad, with unbroken light borders; no light lines on sides of head and neck; no spots on dorsal scales. bulleri (p. 218) 9. Lateral scales with the terminal point arising well within the free posterior margin; dorsal scales 41 or more 10 Lateral scales with the terminal point arising at or very near the free posterior margin; head scales not microscopically rugose; no oblique dark blue lines on throat 11 10. Dorsal scales 47 to 54; throat with very distinct, oblique, dark blue lines;