Chapter I: Part 1

UNIVERSITY OF KANSAS PUBLICATIONS

MUSEUM OF NATURAL HISTORY

Volume 15, No. 1, pp. 1-148, pls. 1-6, 11 figs.

December 20, 1961

[Transcriber's Note: Words surrounded by cedillas, like ~this~ signifies words in bold. Words surrounded by underscores, like _this_, signifies words in italics.]

The Amphibians and Reptiles of Michoacan, Mexico

BY

WILLIAM E. DUELLMAN

UNIVERSITY OF KANSAS LAWRENCE 1961

UNIVERSITY OF KANSAS PUBLICATIONS, MUSEUM OF NATURAL HISTORY

Editors: E. Raymond Hall, Chairman, Henry S. Fitch, Theodore H. Eaton, Jr.

Volume 15, No. 1, pp. 1-148, pls. 1-6, 11 figs. Published December 20, 1961

UNIVERSITY OF KANSAS Lawrence, Kansas

PRINTED IN THE STATE PRINTING PLANT TOPEKA, KANSAS 1961

The Amphibians and Reptiles of Michoacan, Mexico

BY

WILLIAM E. DUELLMAN

CONTENTS

PAGE

INTRODUCTION 3
Acknowledgments 5
Historical Account 7

NATURAL LANDSCAPE 9

GEOGRAPHY OF THE HERPETOFAUNA 13

ANNOTATED LIST OF SPECIES 13
Amphibia 14
Caudata 14
Salientia 20
Reptilia 56
Testudines 56
Crocodilia 58
Sauria 59
Serpentes 88

SPECIES OF QUESTIONABLE OCCURRENCE 124

GAZETTEER 129

SUMMARY 141

LITERATURE CITED 142

INTRODUCTION

For almost 30 years North American herpetologists have been making extensive collections of reptiles and amphibians in Mexico. Some parts of the country, because of their accessibility, soon became relatively well known; other regions lying off the beaten path were bypassed or inadequately sampled. Principally in the last decade herpetologists have been entering regions from which no collections previously were available in an attempt to fill gaps in known distributions and to discover unknown species of animals. In 1950 Dr. Donald D. Brand led an exploration party from the University of Texas to the poorly explored and faunistically unknown region of southwestern Michoacan. James A. Peters accompanied Brand and collected amphibians and reptiles. In 1951 I welcomed the opportunity to accompany Brand on a second expedition to southwestern Michoacan. Such was the beginning of my interest in the herpetofauna of the region. I have been fortunate to return to Michoacan on four successive trips, all of which had as their purpose the accumulation of data on the herpetofauna that would result in a survey of the component species and an analysis of their distribution.

My original intention was to amplify Peters' (1954) study based on the collections made by him in 1950 and by me in 1951 in the Sierra de Coalcoman. But it soon became evident that in order to understand the relationships of the herpetofauna of the Sierra de Coalcoman, the species inhabiting the Tepalcatepec Valley and adjacent mountain ranges would have to be studied. In the course of making that study I examined all specimens from Michoacan already in museums.

There have been few detailed herpetofaunal studies in Mexico. The first such study of any consequence was that by Bogert and Oliver (1945) on the herpetofauna of Sonora. In that paper the authors analyzed the fauna from a geographic view and showed the transition from tropical species in the southern part of the state to members of the Sonoran Desert assemblage to the north. Martin (1958) made a detailed study of the herpetofauna of the Gomez Farias region in southern Tamaulipas; he emphasized the ecological distribution of amphibians and reptiles in that region with special reference to cloud forests. Duellman (1958c) presented a preliminary geographic analysis of the herpetofauna of Colima with special reference to the continuity of the species inhabiting the lowlands. Zweifel (1960) discussed in detail the herpetofauna of the Tres Marias Islands and commented on the derivation of the fauna. Duellman (1960d) provided a detailed account of the geographic distribution of the amphibians known to occur in the lowlands of the Isthmus of Tehuantepec and attempted to account for the present patterns of distribution.

The present report is the first of two parts dealing with the herpetofauna of Michoacan. The purpose of this part is to present a full account of the species of amphibians and reptiles known to inhabit the state of Michoacan; the accounts of the species are accompanied by a brief description of the natural landscape and of the various assemblages of species comprising the major faunistic groups within the region. A gazetteer of collecting localities is appended. The second part of the study, now in preparation, deals with the ecological and historical geography of the herpetofauna. Since the present part will be of interest primarily to systematic herpetologists, I have decided to separate it from the more general material of interest to biogeographers.

One of the major problems that faces the worker undertaking a faunal study is the presence of species or genera of unsettled systematic status. My work in Michoacan has been no exception; fifteen separate studies were undertaken in an attempt to solve systematic problems in certain groups. Some systematic problems still remain but are of little consequence insofar as the entire faunal picture is concerned, or are so involved as to be impractical to undertake at this time. In accounts of species, such problems are mentioned in the hope that they will interest some worker who will be inclined to investigate them.

ACKNOWLEDGMENTS

While engaged in the study of the herpetofauna of Michoacan I have built up a debt of gratitude to many individuals, without whose aid my ambition to complete my study never would have been realized. I am especially grateful to those individuals who accompanied me in the field; Lee D. Beatty, Richard E. Etheridge, Carter R. Gilbert, Fred G. Thompson, Jerome Tulecke, and John Wellman offered stimulating companionship and valuable assistance. On many occasions they suffered hardships on behalf of my interests.

Studies of my own specimens have been augmented by material from other institutions. For permitting me to examine specimens in their care I am indebted to W. Frank Blair, Charles M. Bogert, Doris M. Cochran, William B. Davis, James R. Dixon, the late Emmett R. Dunn, Josef Eiselt, Alice G. C. Grandison, Norman Hartweg, Robert F. Inger, Arthur Loveridge, the late Karl P. Schmidt, Hobart M. Smith, Robert C. Stebbins, Margaret Storey, Edward H. Taylor, and Richard G. Zweifel.

Several people have aided me in the study of specimens and in the analysis of data; I am grateful to Donald D. Brand, who first introduced me to Michoacan; since that time I have benefited much from his knowledge of the area. James A. Peters provided me with essential information concerning his field work in southern Michoacan in 1950. James R. Dixon and Floyd L. Downs have permitted me to use freely the material and data that they accumulated in their recent field work in Michoacan. Norman E. Hartweg allowed me to use the specimens and data that he gathered in his survey of the herpetofauna in the region of Volcan Paricutin. L. C. Stuart, Charles F. Walker, and Richard G. Zweifel have helped in unraveling some of the systematic and distributional problems.

I am especially grateful to my wife, Ann, who for six months helped me track down elusive species and explore new areas. Furthermore, she has stimulated me to carry this study to completion.

Many people in Michoacan favored the field parties with quarters, transportation, and valuable information, which greatly facilitated the field work. In this respect I am especially indebted to Ingeniero Ruben Erbina of Ingenieros Civiles Asociados, who not only let us use his home as our headquarters, but through a letter of introduction gave us the "key" to southern Michoacan. Ingeniero Pedro Tonda aided us in Arteaga and San Salvador. Ingeniero Anastacio Perez Alfaro of the Comision Tepalcatepec in Uruapan provided the latest maps of southern Michoacan and much essential information pertaining to travel conditions in the area. Senor Nefty Mendoza gave us a home in Dos Aguas; this kindness allowed us to work in this interesting region during the height of the rainy season. Mr. and Mrs. Bob Thomas let us make use of their facilities at Hacienda Zirimicuaro. The naval officers at the Estacion Marina at Playa Azul made pleasant what might have been a dreadful stay in that small coastal village. To the managers and pilots of Lineas Aereas Picho in Uruapan I owe special thanks for going out of their way on more than one occasion to transport a stranded snake-hunter. Throughout the months of field work beginning in 1955 I constantly have been aided by the authorities and workers of the Comision Tepalcatepec, a subdivision of the Secretaria de Caminos y Obras Publicas, and of the private corporation, Ingenieros Civiles Asociados. Much of the field work in Michoacan was made possible only through the co-operation of the natives who supplied mules, acted as guides, and aided in the collection of specimens. I have learned a great deal from these people. They will never see this report. Their work as guides, muleteers, and collectors greatly assisted me with the mountains of equipment that had to be piled on the backs of scrawny mules for transportation to places where the natives seldom trod. Their efforts in behalf of Don Guillermo never will be forgotten; I extend an especially hearty _muchas gracias_ to Benjamin, Ignacio, Jesus, Lorenzo, Mariano, and Remigio.

Much of the work on this report was done while I was associated with the Museum of Zoology at the University of Michigan. I thank Norman E. Hartweg and T. H. Hubbell for making available to me the facilities of the museum and for their numerous courtesies that aided me so much.

My field work in Michoacan was supported by the Museum of Zoology at the University of Michigan (1951), by the Horace H. Rackham School of Graduate Studies of the University of Michigan (1955), by the Penrose Fund of the American Philosophical Society (1956), by the Bache Fund of the National Academy of Sciences (1958), and by the University of Kansas Endowment Association (1960).

Permits for collecting specimens in Mexico were provided by the Direccion General de Caza through the courtesy of Ing. Juan Lozano Franco and Luis Macias Arellano.

Historical Account

Unlike many parts of southern Mexico and northern Central America, Michoacan received no attention from the collecting expeditions of the European museums in the last century. The earliest known herpetological specimens from Michoacan were obtained by Louis John Xantus, who was appointed U. S. Consul to Colima in 1859. In April, 1863, Xantus collected at Volcan Jorullo in Michoacan; in April and May of the same year he collected along the coast of Michoacan between the Rio Cachan and the Rio Nexpa. His small collection of 19 extant specimens is in the United States National Museum. Alfredo Duges, a resident of Guanajuato, Mexico, made early contributions to the knowledge of the herpetofauna of Michoacan. In 1885 he described _Sonora michoacanensis_, and in 1891 he described _Eumeces altamirani_; from what is known of the distribution of these species, he probably had collected in the Tepalcatepec Valley. During their biological survey of Mexico, Edward W. Nelson and Edward A. Goldman spent a limited amount of time in Michoacan in 1892 and again in 1903 and 1904. Most of their collecting was done on the plateau in the north-central part of the state; their collections are in the United States National Museum. While collecting fishes in southern Mexico, Seth E. Meek obtained some amphibians and reptiles from Lago de Patzcuaro in 1904; these are in the collections of the Chicago Natural History Museum. In 1908 Hans Gadow ventured into the then unexplored "tierra caliente" of the Balsas Valley and collected at Volcan Jorullo and other localities in the valley. Later in the same year he collected at Guayabo, San Salvador, and Arteaga in the Sierra de Coalcoman and at Buena Vista and Cofradia in the Tepalcatepec Valley. His collections were deposited in the British Museum (Natural History) and the Naturhistorisches Museum Wien.

The first thirty years of the present century saw little more field work in Michoacan. In the 1930's Edward H. Taylor and Hobart M. Smith collected throughout much of Mexico. At various times they worked in Michoacan, principally along the road from Mexico City to Guadalajara. In 1935 Hobart M. Smith spent a week at Hacienda El Sabino south of Uruapan; he revisited the locality again in 1936 and made a large and important collection of amphibians and reptiles from the upper limits of the arid tropical scrub forest in the Tepalcatepec Valley. Specimens collected by Smith and Taylor were incorporated into the Edward H. Taylor-Hobart M. Smith collection, which subsequently was deposited in part in the Museum of Natural History at the University of Illinois and in part in the Chicago Natural History Museum. In 1939 Hobart M. Smith collected at Patzcuaro and between Uruapan and Apatzingan; these collections, made while he was a Walter Rathbone Bacon Scholar of the Smithsonian Institution, are deposited in the United States National Museum. In 1940 and 1941 Frederick A. Shannon, who was a member of the Hoogstraal Expeditions under the auspices of the Chicago Natural History Museum, collected on Cerro de Tancitaro and at Apatzingan; an account of the specimens collected there was published by Schmidt and Shannon (1947).

The eruption of Volcan Paricutin in February, 1943, attracted the attention of many biologists, a group of which from the Museum of Zoology at the University of Michigan collected in the Cordillera Volcanica in 1945 and 1947. The amphibians and reptiles were collected and studied by Norman E. Hartweg. In 1950 James A. Peters accompanied Donald D. Brand on a preliminary exploration of the western part of the Sierra de Coalcoman and adjacent Pacific coast of Michoacan; in the same year Peters collected also on the Mexican Plateau and at Volcan Jorullo. His specimens are in the Museum of Zoology at the University of Michigan. Since 1950 many biologists have collected in Michoacan in the course of work on certain groups of animals or in general surveys. In this way Raymond Alcorn, Robert W. Dickerman, James R. Dixon, Floyd L. Downs, Emmet T. Hooper, and Robert R. Miller have contributed to our knowledge of the herpetofauna.

As stated previously, my own field work in Michoacan began in 1951, when I accompanied Donald D. Brand on an exploring expedition to the southern part of the state. In that year a short time was spent on the Mexican Plateau, principally in the area around Lago de Cuitzeo, and at Volcan Jorullo. In July and August we made our headquarters at Coalcoman. From that town the field party travelled southward to Maruata on the Pacific coast and thence back over the mountains to Coalcoman. Later in that summer we travelled by mule from Coalcoman southeastward to the mouth of the Rio Nexpa. In 1955, accompanied by Lee D. Beatty, Carter R. Gilbert, and Fred G. Thompson, I collected in the Tepalcatepec Valley and at Coalcoman. We made a mule trip from Coalcoman to Cerro de Barolosa, where we made the first collections from the pine-fir forests in the Sierra de Coalcoman. Later in the same summer Carter R. Gilbert and I spent a week at Playa Azul on the Pacific coast. In March, April, and May, 1956, my wife and I collected for a short time in the Cordillera Volcanica and on the Mexican Plateau. In early April we moved into the Tepalcatepec Valley, where we collected intensively between Churumuco and Tepalcatepec. In May we collected on the Pacific coast between Boca de Apiza and La Placita. In July and August, 1956, accompanied by Richard E. Etheridge, we returned to Michoacan and again collected on the Mexican Plateau and in the Cordillera Volcanica, before moving into the Tepalcatepec Valley. In an attempt to fill in gaps in the known distributions of many species and to sample the fauna in some previously uncollected areas, I returned to Michoacan in June, 1958. Accompanied by Jerome B. Tulecke and John Wellman, I collected on the Mexican Plateau in the northwestern part of the state, on the southern slopes of the Cordillera Volcanica, and in the Tepalcatepec Valley. Most of our time was spent in the Sierra de Coalcoman, where we collected at Aguililla, Artega, and Dos Aguas. In 1960 two days were spent in Michoacan; a small collection was made in the eastern part of the Cordillera Volcanica. With the exception of the specimens collected in 1960, which are at the Museum of Natural History at the University of Kansas, the specimens that I have collected in Michoacan are in the Museum of Zoology at the University of Michigan.

NATURAL LANDSCAPE

A proper understanding of the geographical distribution of animals in a given region is possible only after a thorough acquaintance with the geography of the region. Likewise, in order to gain a knowledge of the ecological distribution and relationships of the components of the fauna, it is necessary to study the animals in their natural environments. In order to give the reader a picture of the physical features and the major animal habitats within the state of Michoacan, the following brief description is offered. Each of these facets mentioned below will be elaborated in detail in my final report on the herpetofauna of Michoacan.

Physiography

The state of Michoacan comprises an area of 60,093 square kilometers (Vivo, 1953). Within this area the rugged terrain has a total relief of nearly 4000 meters. There have been several attempts to classify the physiographic provinces of Mexico; the classification used here is a slight modification of the scheme proposed by Tamayo (1949). I have tried to keep the system as simple as possible, but still useful in discussing the distribution of animals living in the region. For general purposes the state of Michoacan can be divided into lowlands and highlands as follows:

LOWLANDS
Pacific Coastal Plain
Balsas-Tepalcatepec Basin

HIGHLANDS
Mexican Plateau
Cordillera Volcanica
Sierra de Coalcoman

Although the lowlands in the state are continuous, they are only narrowly connected and thus form two distinct physiographic and biotic areas. The Pacific Coastal Plain in Michoacan extends for a distance of about 200 kilometers (airline) from the Rio Coahuayana to the Rio Balsas. The coastal plain is broad between the Rio Coahuayana and San Juan de Lima, and between Las Penas and the Rio Balsas, where the hills rise some 12 kilometers inland from the sea. Between San Juan de Lima and Las Penas the mountains extend to the sea; in this region rocky promontories form precipitous cliffs dropping into the sea. Between the promontories are small sandy or rocky beaches.

Lying to the north of the Sierra de Coalcoman and the Sierra del Sur, but south of the Cordillera Volcanica, is a broad structural depression, the Balsas-Tepalcatepec Basin. The western part of this basin, which separates the Sierra de Coalcoman from the Cordillera Volcanica, is the valley of the Rio Tepalcatepec, a major tributary of the Rio Balsas. The eastern part of the basin is the valley of the Rio Balsas. From the point of junction of the two rivers, the Rio Balsas flows southward through a narrow gorge, which separates the Sierra de Coalcoman from the Sierra del Sur, to the Pacific Ocean. In Michoacan the floor of the Balsas-Tepalcatepec Basin varies from 200 to 700 meters above sea level.

The central part of Mexico is a vast table-land, the Mexican Plateau, the southern part of which extends into northern Michoacan. In this region the terrain is rolling and varies from 1500 to 1900 meters above sea level. Many small mountain ranges rise from the plateau and break the continuity of the rolling table-land. Located on the southern part of the Mexican Plateau in Michoacan are several lakes, the largest of which are Lago de Chapala, Lago de Cuitzeo, and Lago de Patzcuaro.

Bordering the southern edge of the Mexican Plateau is a nearly unbroken chain of volcanos, the Cordillera Volcanica. The highest peaks in Michoacan, Cerro San Andres (3930 meters) and Cerro de Tancitaro (3870 meters), are in this range. Parts of the Cordillera Volcanica in Michoacan are known by separate names; these are, from west to east: Sierra de los Tarascos, Sierra de Ozumatlan, and Serrania de Ucareo.

Lying between the Tepalcatepec Valley and the Pacific Ocean, and east of the Rio Coahuayana and west of the Rio Balsas, is an isolated highland mass, the Sierra de Coalcoman. This mountain range rises to elevations of slightly more than 3000 meters. It has a length of about 200 kilometers and a width of about 80 kilometers. Except for a relatively low connection with the Cordillera Volcanica, the Sierra de Coalcoman is isolated from other mountain ranges in southwestern Mexico.

CLIMATE

The climates in Michoacan vary from tropical in the lowlands to cool temperate at high elevations in the Sierra de Coalcoman and Cordillera Volcanica. The highest temperatures are known in the Balsas-Tepalcatepec Basin, where at Churumuco the mean annual temperature is 29.3 deg. C. and the range of monthly means is 3.5 deg. C. (Contreras, 1942). Frosts occur sporadically on the Mexican Plateau, and in the winter snow falls on the highest mountains.

Precipitation varies geographically and seasonally. Most of the rain falls between June and October. In the Balsas-Tepalcatepec Basin rainfall in the rest of the year is negligible. The annual average rainfall at Coahuayana on the Pacific Coastal Plain is 871 mm. (Guzman-Rivas, 1957:52). In the Balsas-Tepalcatepec Basin rainfall seldom exceeds 800 mm. per year. In the mountains precipitation is heavier and somewhat more evenly distributed throughout the year, but still definitely cyclic. For example, Uruapan (elevation, 1500 meters) receives an average annual rainfall of 1674 mm. (Contreras, 1942). The prevailing winds are from the Pacific Ocean. The southern (windward) slopes of the Sierra de Coalcoman probably receive more rain than any other part of the state. The Balsas-Tepalcatepec Basin lies in a rain shadow of the Sierra de Coalcoman, and the Mexican Plateau lies in a somewhat less drastic rain shadow of the Cordillera Volcanica; these are the driest regions in the state.

VEGETATION AND ANIMAL HABITATS

For the purposes of this report I have adopted the classification of types of vegetation that seem to me most significant in terms of ecological distribution of reptiles and amphibians in Michoacan. These types are as follows:

TEMPERATE (1000-4000 meters)
Fir Forest (2400-4000 meters)
Pine-oak Forest (1000-4000 meters)
Mesquite-grassland (1500-2100 meters)

TROPICAL (0-1000 meters)
Arid Tropical Scrub Forest (0-1000 meters)
Tropical Semi-deciduous Forest (150-600 meters)

The vegetation of the Pacific Coastal Plain and the Balsas-Tepalcatepec Basin consists of arid tropical scrub forest, composed of deciduous trees, which in many places are stunted and widely spaced. In the dry season there is little cover provided by this forest. In the rainy season there is a sparse growth of grasses and some shade provided by the small leaves of the thorny trees.

In Michoacan the rainfall is heaviest on the southern slopes of the Sierra de Coalcoman and somewhat less so on the southwestern slopes of the Cordillera Volcanica. At these relatively low elevations (150 to 600 meters) there is tropical semi-deciduous forest, characterized by relatively dense shade throughout the year and by a leaf mulch on the ground. This type of forest forms the gallery forest along the larger streams in the Balsas-Tepalcatepec Basin and on the Pacific Coastal Plain.

Rainfall also is heavy on the high mountain ridges, where temperatures are low. On these ridges, fir forest, often mixed with pine and oaks, is found. This habitat is characterized by a cool, moist climate, many rotting logs, and a moist ground cover of leaves and needles.

Most of the mountains are covered with pine-oak forest, which in most places is decidedly subhumid, but where this forest occurs on the windward sides of high ridges, it sometimes is noticeably humid. In this forest the important animal habitats include the needle- and leaf-litter, and in some areas, bromeliads.

The rolling terrain of the Mexican Plateau supports cacti, small leguminous trees, and grasses. Like the arid tropical scrub forest, this type of vegetation, the Mesquite-grassland association, is deciduous and thus provides little shelter in the dry season. Unlike the areas in which arid tropical scrub forest is developed, the Mesquite-grassland is found in areas having warm days and cool nights.

GEOGRAPHY OF THE HERPETOFAUNA

Although the main part of my final report on the herpetofauna of Michoacan will deal with the geographical and ecological patterns of distribution of the herpetofauna, a brief summary of the faunal assemblages is presented here.

In Michoacan there are two major faunal assemblages, one in the lowlands, and one in the highlands. A large number of the species inhabiting the lowlands are wide-ranging species, such as _Bufo marinus_, _Iguana iguana_, and _Boa constrictor_. Sixty-three species are known to occur on the Pacific Coastal Plain; 41 of these, together with 36 others occur in the Balsas-Tepalcatepec Basin, a physiographic region to which several species of reptiles are endemic; for example, _Enyaliosaurus clarki_, _Urosaurus gadowi_, _Cnemidophorus calidipes_, and _Eumeces altamirani_.

Generally speaking, the members of the highland faunal assemblage have more restricted geographic ranges. The major exceptions are those species that are widely distributed on the Mexican Plateau, such as: _Bufo compactilis_, _Sceloporus torquatus_, and _Salvadora bairdi_. In the montane habitats of the Cordillera Volcanica, 45 species of amphibians and reptiles are known; 34 species have been found in the Sierra de Coalcoman. Fourteen species are known to occur in both ranges. Several species are known only from the Cordillera Volcanica and adjacent highlands, and three species are endemic to the Sierra de Coalcoman.

ANNOTATED LIST OF SPECIES

In the following pages the 176 species and subspecies of amphibians and reptiles known to occur in the state of Michoacan are discussed in relation to their variation, life histories, ecology, and distribution in the state. Data have been gathered from 9676 specimens. I have not prolonged the accounts of species with information that has been presented elsewhere. Consequently, the length and completeness of the accounts are variable. I have given only the information that I consider a worthwhile contribution to our knowledge of the particular species.

The synonymies given at the beginning of each account include the first use of the trivial name by the original author, the first usage of the combination that I am using, and, if the circumstances make it necessary, additional names or combinations that have been proposed since the publication of the checklists of Mexican amphibians and reptiles by Smith and Taylor (1945, 1948, and 1950b). References cited only in the synonymies are not listed in the Literature Cited. Preceding the discussion of each species is an alphabetical list of the localities in Michoacan from which specimens have been examined. The listing of a locality means that one or more specimens, as indicated, has been examined from that locality. Only for those specimens especially mentioned in the text are catalogue numbers given. Abbreviations for the various museums and scientific collections are, as follows:

AMNH American Museum of Natural History
ANSP Academy of Natural Sciences of Philadelphia
BMNH British Museum (Natural History)
CNHM Chicago Natural History Museum
EHT-HMS Edward H. Taylor-Hobart M. Smith collection
JRD James R. Dixon collection, College Station, Texas
KU University of Kansas Museum of Natural History
MCZ Museum of Comparative Zoology
MVZ Museum of Vertebrate Zoology
NMW Naturhistorisches Museum Wien
SU Stanford University Museum of Natural History
TCWC Texas Cooperative Wildlife Collection
UIMNH University of Illinois Museum of Natural History
UMMZ University of Michigan Museum of Zoology
USNM United States National Museum
UTNHC University of Texas Natural History Collection

Throughout the accounts of the species all measurements are given in millimeters; if the range of variation is given, the mean follows in parentheses.

AMPHIBIA

Caudata

~Ambystoma amblycephalum~ Taylor

_Ambystoma amblycephala_ Taylor, Univ. Kansas Sci. Bull.,
26: 420, November 27, 1940.--Fifteen kilometers west of
Morelia, Michoacan, Mexico.

Fifteen km. W of Morelia (19); 11 km. SSE of Opopeo (12); 8
km. S of Patzcuaro; 24 km. S of Patzcuaro (2); Quiroga (20);
Tacicuaro (167).

Taylor and Smith (1945:530) presented data on 137 specimens collected at Tacicuaro on October 1, 1939; these are all larvae and metamorphosing individuals. Aside from these, the largest larva examined (UMMZ 104962 from 15 km. W of Morelia) has a snout-vent length of 70.0 mm. and a tail length of 53.5 mm. The larvae are pale pinkish tan above and somewhat paler below; there is a lateral row of cream colored spots. The tail-fin, which is deepest at mid-length, extends to the back of the head and is flecked with brown. In small larvae the outer edge of the tail-fin is dark brown. The eyes are large. Two small metamorphosed specimens (UMMZ 98967) from 24 kilometers south of Patzcuaro are tentatively referred to this species. These specimens have body lengths of 49.0 and 45.0 mm. and tail lengths of 36.0 and 31.5 mm., respectively. They have 17-17 and 16-15 vomerine teeth arranged in a broad arch behind the choanae, 10 costal grooves, and 7 intercostal spaces between adpressed toes. The dorsal color is uniform brown; that of the venter is a dusty cream.

Larvae were collected from shallow ponds near Quiroga and 15 kilometers west of Morelia; metamorphosed individuals were taken from beneath logs in pine and fir forests at elevations from 2300 to 2800 meters.

~Ambystoma dumerili dumerili~ (Duges)

_Siredon Dumerili_ Duges, La Naturaleza, 1:241, 1870--Lago
de Patzcuaro, Michoacan, Mexico.

_Bathysiredon dumerilii_, Dunn, Notulae Naturae, 36:1,
November 9, 1939.

_Bathysiredon dumerilii dumerilii_, Maldonado-Koerdell, Mem.
y Rev. Acad. Nac. Cien., 56:199, 1948.

_Ambystoma_ (_Bathysiredon_) _dumerili_, Tihen, Bull.
Florida State Mus., 3:3, June 20, 1958.

Lago de Patzcuaro (22);? Morelia.

For many years this unusual salamander was known from only a few specimens mostly collected in the last century; Smith and Taylor (1948:7) stated: "It is presumed that this species is extinct owing to the introduction of exotic game and food fishes." In 1951 and in 1955 I had been told that _axolotls_ were sold in the market at Patzcuaro; nevertheless, none was found on my visits there. In 1956 Charles M. Bogert obtained several large specimens at the market in Patzcuaro. These establish the continued existence of the salamander in Lago de Patzcuaro. On January 27, 1955, R. W. Dickerman procured a specimen (KU 41573) in the market at Morelia. Since fish are brought to Morelia from Lago de Patzcuaro, the specimen probably was from that lake. Nevertheless, the species may occur in other permanent bodies of water in Michoacan. Maldonado-Koerdell (1948) described _Bathysiredon dumerili queretarensis_ from San Juan del Rio, Queretaro. This locality is about 200 airline kilometers northeast of Lago de Patzcuaro and is in the Rio Moctezuma drainage.

~Ambystoma ordinarium~ Taylor

_Ambystoma ordinaria_ Taylor, Univ. Kansas Sci. Bull.,
26:422, November 27, 1940.--Four miles west of El Mirador,
near Puerto Hondo, Michoacan, Mexico.

Axolotl (56); Cerro San Andres; 22 km. W of Mil Cumbres; 46
km. E of Morelia (34); 8 km. SE of Opopeo (5); Puerto de
Garnica (8); Puerto Hondo (41); San Gregorio (16); San Jose
de la Cumbre (20).

Of 16 specimens (KU 51520-35) collected on June 18, 1955, near San Gregorio, 15 are adult females with swollen cloacae and minute ovarian eggs. Possibly these specimens had just recently deposited their mature eggs. In preservative the specimens are black above and dull creamy gray below. Measurements for the 15 females are: snout-vent length, 80.0-102.0 (92.5); tail length, 69.0-93.0 (84.2); head width, 15.8-20.5 (17.7); head length, 22.8-26.6 (24.4). A larval specimen with small gills has a snout-vent length of 72 mm. and a tail length of 62 mm. Three specimens have 12 costal grooves; the other have 11.

Of 20 specimens from San Jose de la Cumbre (UMMZ 112857 and 115143), 14 are neotenic adults; the others are larvae. In life the salamanders were blackish to olive-brown above with scattered cream-colored dots on the dorsum and flanks but in preservative are dull grayish black with indistinct pale spots and dark reticulations. The belly is pale gray with indistinct dark spots. Eleven females and three males have the following measurements, respectively: snout-vent length, 76.0-90.0 (80.7), 64.0-84.0 (74.3); tail length, 70.0-81.0 (75.0), 58.0-71.0 (66.7); head width, 19.5-23.5 (20.7), 17.5-20.5 (19.3); head length, 22.0-25.0 (23.0), 20.0-22.5 (21.5). The smallest larva has a snout-vent length of 43.0 mm. and a tail length of 38.0 mm. Two individuals have 12 costal grooves; the others have 11. All of the females contained eggs, the largest of which were 1.5 mm. in diameter. The stomachs of most of the specimens were distended with oligochaets, aquatic insect larvae, and small aquatic beetles.

A series of 34 larvae (JRD 5904-37) from 46 kilometers east of Morelia are tentatively referred to this species. These specimens are olive-brown above with cream-colored spots on the flanks; the dorsal tail-fin does not extend onto the body.

This species has been found only at elevations in excess of 2400 meters in pine and fir forests. At Rancho Axolotl James A. Peters collected larvae and neotenic individuals in a rocky stream and adults from beneath rocks and logs in the forest near the stream. Neotenic individuals and larvae were found in a clear stream in pine-fir forest at an elevation of 2700 meters near San Jose de la Cumbre; specimens were collected there in July, 1955, and again in July, 1956. The site was visited in April, 1956, at which time the stream consisted of only a few puddles; no salamanders were found.

~Ambystoma tigrinum velasci~ Duges

_Ambystoma velasci_ Duges, La Naturaleza, ser. 2, 1:142,
1888.--Laguna Santa Isabel, near Guadalupe Hidalgo, Distrito
Federal, Mexico.

_Ambystoma tigrinum velasci_, Dunn, Copeia, no. 3:157,
November 14, 1940.

Patzcuaro (5); Tacicuaro (9).

Definite specific assignment of these specimens, all larvae, cannot be made at this time. They have shovel-shaped heads and laterally compressed bodies with the dorsal tail-fin extending anteriorly to the back of the head. The eyes are small. The body is pale tan with dark mottling on the tail and flanks. The average snout-vent length for nine specimens from Tacicuaro is 61.0 mm.

The larvae from Tacicuaro (UMMZ 89255) were collected by Dyfrig Forbes in October, 1939; those from Patzcuaro, presumably Lago de Patzcuaro (BMNH 1914.1.28-247-8 and CNHM 948), were collected by Hans Gadow and Seth Meek in 1908.

~Pseudoeurycea belli~ (Gray)

_Spelerpes belli_ Gray, Catalogue Batrachia Gradientia
British Museum, p. 46, 1850.--Mexico. Type locality
restricted to 2 miles east of Rio Frio, Puebla, Mexico, by
Smith and Taylor (1950a:341).

_Pseudoeurycea bellii_, Taylor, Univ. Kansas Sci. Bull.,
30:209, June 12, 1944.

Axolotl (2); Carapan; Cerro Tancitaro (84); Macho de Agua;
22 km. W of Mil Cumbres; Opopeo; Patzcuaro (8); Puerto Hondo
(2): San Jose de la Cumbre; San Juan de Parangaricutiro
(42); Uruapan (5); Zacapu (4).

This salamander seems to reach its greatest abundance in Michoacan in the Sierra de los Tarascos between Patzcuaro and Tancitaro, where it is found at elevations from 1500 to 2900 meters. It is found less commonly in the eastern part of the Cordillera Volcanica in Michoacan, where it sometimes occurs in association with _Pseudoeurycea robertsi_.

On June 22 and 23, 1955, four clutches of eggs of this species were found beneath adobe bricks and rocks on the volcanic ash that has buried the village of San Juan de Parangaricutiro. The eggs were unstalked and separate, but adherent in clumps of three or four (Pl. 2, Fig. 1). The outer membranes were covered with fine particles of ash. The ash beneath the stones where the eggs were found was only slightly moist; one clump of eggs was partially desiccated. Three complete clutches have 20, 23, and 34 eggs; one clutch of 15 eggs was being eaten by beetles (Tenebrionidae: _Eleodes_ sp.). The eggs vary in size from 4.6 to 6.5 mm. and average 5.3 mm. in diameter. They are unpigmented. Surrounding the embryo is a vitelline membrane, an inner, and an outer envelope (Fig. 1). In an average-sized egg having an embryo 4 mm. in length, the diameter of the outer membrane is 5.3 mm., the inner membrane 5.0 mm., and the vitelline membrane 4.6 mm. All of the eggs contained embryos in which the limb buds were developed; in about half of these the eyes were distinctly visible.

The first heavy rain of the season occurred on the night of June 22, 1955. Thus, at least sometimes, _Pseudoeurycea belli_ lays its eggs before the onset of the rainy season. A female having a snout-vent length of 110 mm., collected on June 22, 1955, contained 36 ovarian eggs having diameters from 3.0 to 3.5 mm. The fact that small juveniles were collected on the same date indicates that this salamander lays eggs over a period of several weeks in late spring and early summer.

The smallest juvenile examined has a snout-vent length of 17.0 mm. and a tail length of 7.5 mm. Twelve juveniles from the vicinity of San Juan de Parangaricutiro have an average snout-vent length of 19.4 mm. and an average tail length of 9.7 mm. In juveniles the adpressed limbs either touch or overlap by one intercostal space; in adults there are two or three intercostal spaces between adpressed toes. Therefore the greatest number of intercostal spaces between adpressed limbs is found in the largest specimens. A similar relationship between adpressed limbs (= length of limbs) and snout-vent length was shown for _Plethodon richmondi_ by Duellman (1954a). The number of vomerine teeth is variable; the number of teeth seems to be closely correlated with the size of the salamander (Fig. 2). A similar correlation between the number of maxillary teeth and body length was reported for _Chiropterotriton multidentatus_ by Rabb (1958). In 12 juvenile _Pseudoeurycea belli_ there are 6-13 (8.8) vomerine teeth, and in 11 adults having snout-vent lengths greater than 90 mm. there are 39-49 (44.0) vomerine teeth. The coloration of the juveniles resembles that of the adults (Pl. 1).

The differences between this species and _Pseudoeurycea gigantea_ are minor. Taylor (1939a) distinguished _gigantea_ from _belli_ by the larger size, fewer intercostal spaces between adpressed limbs, more vomerine teeth, and absence of occipital spots in _gigantea_. Taylor and Smith (1945) stated that in life the spots in _gigantea_ are orange instead of red as in _belli_. Five specimens of _Pseudoeurycea belli_ from Michoacan, including one juvenile, lack occipital spots. In the 34 living individuals that I have seen from Michoacan the spots varied from deep red to orange. Therefore, of the characters listed by Taylor (_op. cit._) to diagnose _Pseudoeurycea gigantea_, only the over-all larger size and smaller number of intercostal spaces between adpressed limbs (= relatively longer limbs) are useful in separating _Pseudoeurycea belli_ and _gigantea_.

~Pseudoeurycea robertsi~ (Taylor)

_Oedipus robertsi_ Taylor, Univ. Kansas Sci. Bull., 25:287,
July 10, 1939.--Nevado de Toluca, Mexico.

_Pseudoeurycea robertsi_ Taylor, Univ. Kansas Sci. Bull.,
30:209, June 12, 1944.

Atzimba (3); Macho de Agua (9); Puerto Lengua de Vaca (14).

Previously this species has been recorded only from the type locality. In July, 1956, individuals referable to this species were found at two sites in pine-fir forest immediately to the east of Macho de Agua and in pine-oak-fir forest at Atzimba. On August 20, 1958, a series was collected in pine-fir forest at Puerto Lengua de Vaca. These localities are between 2900 and 3000 meters in the Cordillera Volcanica in eastern Michoacan.

In life the coloration of these salamanders was highly variable. The belly and undersurfaces of the tail and hind limbs were pale gray, with or without silvery white flecks; the chin was a cream-color and flecked with silvery white in some specimens. The middorsal area was brown, orange-brown, or dull grayish yellow. The flanks and lateral surfaces of the tail were black with yellowish flecks or streaks on the flanks and yellowish or orange-brown flecks on the tail. The iris was golden brown. Measurements of eight males and two females are, respectively: snout-vent length, 42.5-56.0 (49.5), 54.0-60.0 (57.0); tail length, 42.0-56.0 (48.1), 52.0-55.0 (53.5). The smallest juvenile has a snout-vent length of 28.0 mm. and a tail length of 23.0 mm. Of the 26 available specimens, six have 12 costal grooves, and the others have 11.

In comparison with 36 topotypes, the specimens from Michoacan have a less striking dorsal color pattern; none has a well-defined dorsal reddish brown area or bold reddish mottling on the tail. Furthermore, the specimens from Michoacan have paler venters than do topotypic specimens.

Salientia

~Rhinophrynus dorsalis~ Dumeril and Bibron

_Rhinophrynus dorsalis_ Dumeril and Bibron, Erpetologie
generale, vol. 8:758, 1841.--Veracruz, Veracruz, Mexico.

Mouth of the Rio Balsas (10).

These specimens (BMNH 1914.1.28.181-90) were collected by Gadow in 1908 and reported by him (1930:72): "Whilst this very sluggish termite-eating toad is common enough in the sweltering hot country of the state of Vera Cruz, up to an elevation of 1500 feet, it was unknown on the west side of the Isthmus until I found it in great numbers near the mouth of the Balsas River, in and near fresh-water pools, where it attracted attention by its loud peculiar voice during the pairing season in the month of July." Subsequently, Peters (1954:3) verified the identification of these specimens. Although torrential rains fell during the week in July, 1955, that I spent at Playa Azul near the mouth of the Rio Balsas, the distinctive voice of _Rhinophrynus_ was not heard. Elsewhere on the Pacific coast of Mexico adult _Rhinophrynus_ have been reported only from Tehuantepec and a few localities on the coastal lowlands of Chiapas. Taylor (1942b:37) found on the coast of Guerrero a tadpole that was referred to the genus _Rhinophrynus_ by Orton (1943). In the summer of 1960 adults of _Rhinophrynus_ were collected near Acapulco, Guerrero (Fouquette, _in litt._). These recent collections verify the existence of the species along the Pacific lowlands of Mexico at least as far north as Michoacan.

~Scaphiopus hammondi multiplicatus~ Cope

_Scaphiopus multiplicatus_ Cope, Proc. Acad. Nat. Sci.
Philadelphia, 15:52, June 8, 1863.--Valley of Mexico.

_Scaphiopus hammondi multiplicatus_, Kellogg, Bull. U. S.
Natl. Mus., 160:22, March 31, 1932.

Angahuan (5); Cuitzeo (4); Cuseno Station (2); Jiquilpan
(9); Morelia (7); Patzcuaro (3); Quiroga; Tarecuaro; Uruapan
(24); Zacapu.

This small toad has been found at elevations between 1500 and 2500 meters on the Mexican Plateau and associated mountain ranges; it occurs in mesquite-grassland and in pine forests. Calling males and females laden with eggs have been collected in the rainy season in the months of July and August. The call is a medium-pitched snore. In living individuals the dorsal ground color varies from pale brown to gray with dark brown or olive-brown markings. In many individuals the tips of the small dorsal pustules are red.

~Bufo coccifer~ Cope

_Bufo coccifer_ Cope, Proc. Acad. Nat. Sci. Philadelphia,
18:130, 1866--Arriba, Costa Rica.

Apatzingan (27); Lombardia; Nueva Italia (5).

In life the dorsal color pattern consists of a yellowish tan ground color with dark brown spots; the middorsal stripe is deep yellow or cream color. The venter is a dusty cream color, and the iris is pale gold. Males have dark brown horny nuptial tuberosities on the thumb. The following measurements are of 21 males and four females, respectively: snout-vent length, 43.5-51.7 (48.1), 55.6-62.6 (59.1); tibia length, 16.6-18.8 (17.6), 18.8-20.3 (19.3); head width, 16.7-19.7 (18.4), 20.6-22.2 (21.4); head length, 13.8-16.6 (14.8), 16.5-18.2 (17.3).

The specimens from the Tepalcatepec Valley differ slightly from specimens from southeastern Mexico and Central America. Those from Michoacan have low and narrow cranial crests; in about one-half of the specimens the occipital crest exists only as a row of tubercles, and in some the postorbital and suborbital crests are barely discernible. Specimens from the southern part of the range, Costa Rica and Nicaragua, have much higher and thicker cranial crests; in these the occipital crest is well defined and extends posteriorly to a point back of the anterior edge of the parotid gland; the postorbital and suborbital crests are well marked. Of 48 specimens from Esquipulas, Guatemala, all have high crests, but these are not so well developed as in ten specimens from Matagalpa, Nicaragua, and three from various localities in Costa Rica. Six specimens from Tehuantepec, Oaxaca, have cranial crests that are lower than those in specimens from Guatemala. In three of the specimens from Tehuantepec the occipital crests are reduced to a series of tubercles. Of six specimens from Agua del Obispo, Guerrero, four have poorly developed occipital crests. These observations suggest the presence of a cline in the development of the cranial crests; specimens have higher crests in the southern part of the range than in the northern part.

In Mexico _Bufo coccifer_ has been collected only in semi-xeric habitats, but to the south, from Guatemala to Costa Rica, it has been found in more upland and humid habitats. Southern specimens are darker than those from the north, a possible correlation with the differences in habitat.

These toads probably range throughout the Tepalcatepec Valley, but they are unknown from the coast of Michoacan. Breeding choruses were found after heavy rains on June 24, 1955, and on August 2, 1956. The first was in a muddy ditch; the second was in a flooded grassy field. The call is a high-pitched, but not loud, "whirrr." Males were calling from the edge of the water or from clumps of grass in the water. Clasping pairs were in the water; amplexus is axillary.

~Bufo compactilis compactilis~ Wiegmann

_Bufo compactilis_ Wiegmann, Isis von Oken, 26:661,
1833.--Mexico. Type locality restricted to Xochimilco,
Distrito Federal, Mexico, by Smith and Taylor (1950a:330).

_Bufo compactilis compactilis_, Smith, Herpetologica, 4:7,
September 17, 1947.

Cuitzeo (2); Emiliano Zapata (20); Jiquilpan (5); La Palma
(5); Morelia; Tupataro.

The southwestern terminus of the range of this species is on the Mexican Plateau in Michoacan. All specimens from the state have spotted venters. In living toads the dorsal ground color was gray or grayish tan with olive green spots. The vocal sac was brownish gray; the iris was a bright golden color.

On June 11, 1958, many individuals were calling from shallow water in a flooded field at Emiliano Zapata. The call is a slow trill, in which the individual notes are discernible.

~Bufo marinus~ (Linnaeus)

_Rana marina_ Linnaeus, Systema naturae, ed. 10, 1:211,
1758.--America.

_Bufo horribilis_ Wiegmann, Isis von Oken, 26:654,
1833.--Misantla and Veracruz, Veracruz, Mexico. Taylor and
Smith, Proc. U. S. Natl. Mus., 95:551, January 30, 1945.

_Bufo angustipes_ Taylor and Smith, Proc. U. S. Natl. Mus.,
95:553, January 30, 1945.--La Esperanza, Chiapas, Mexico.

Aguililla; Apatzingan (3); Barranca de Bejuco; Capirio;
Charapendo; Chichihuas; Coahuayana (2); Coalcoman (7);
Cofradia (2); 25 km. S of Cuatro Caminos; El Sabino (10);
Huahua, La Playa (13); Ojos de Agua de San Telmo; Ostula;
Playa Azul (2); Pomaro (2).

This large toad is characteristically found in areas supporting tropical scrub forest to elevations of about 1000 meters. The species is much more abundant than the numbers listed above suggest. In the dry season individuals have been observed in patios, along streams, and by irrigation ditches. In the rainy season the loud, rattling call of the males is heard at night throughout the Tepalcatepec Valley and the coastal lowlands.

Taylor and Smith (1945:552) revived Wiegmann's _Bufo horribilis_ for the large toads of Mexico that are here referred to _B. marinus_. Their action was based upon the supposition that the "species _marinus_" is composite. Although probably true, this supposition has yet to be proved. Until the large, and apparently related, species of _Bufo_ inhabiting tropical America have been studied systematically as a unit, the recognition of segments of the population as either species or subspecies is meaningless. Taylor and Smith (op. cit.:553) based the description of a new species, _Bufo angustipes_, on one rather emaciated, formalin-hardened female from La Esperanza, Chiapas. The type (USNM 116513), when compared with numerous specimens of _Bufo marinus_ from throughout the range of the species in Mexico and northern Central America, displays no combination of characters to set it off from the others. Therefore, I suggest that _Bufo horribilis_ Wiegmann and _Bufo angustipes_ Taylor and Smith be placed in the synonymy of _Bufo marinus_ (Linnaeus) until future systematic study of the genus and this species in particular establishes the existence of recognizable taxa.

~Bufo marmoreus~ Wiegmann

_Bufo marmoreus_ Wiegmann, Isis von Oken, 26:66,
1833.--Veracruz, Veracruz, Mexico.

Barranca de Bejuco; Coahuayana (11); El Diezmo (2); La
Placita (9); La Orilla (12); Motin del Oro; Ostula (9);
Playa Azul (5); Pomaro (15); Salitre de Estopilas; San Pedro
Naranjestila.

In Michoacan this species is confined to elevations of less than 1000 meters on the coast and foothills of the Sierra de Coalcoman. In this region in the months of June and July, breeding congregations have been found in temporary pools and along streams.

Smith and Taylor (1948:39), in their key to the Mexican species of _Bufo_, placed emphasis on the nature of the supraorbital and postorbital crests (whether they form a curve or a sharp angle) in distinguishing _Bufo marmoreus_ from _Bufo perplexus_. In the original description of _perplexus_, Taylor (1943a:347) characterized the species as follows: supraorbital and postorbital crests forming a sharp angle, instead of a curve as in _marmoreus_; supratympanic crest smaller than in _marmoreus_; diagonal lateral stripe lacking in females; concentration of dorsal tubercles as found in _marmoreus_ lacking in males. The discovery of specimens in which the crests form a curve and others in which the crests form an angle in both the Tepalcatepec Valley and in the coastal lowlands prompted an investigation of these characters and others throughout the ranges of the species. An examination of 410 specimens has resulted in the following conclusions.

TABLE 1.--VARIATION IN THE SHAPE OF THE SUPRAORBITAL AND POSTORBITAL CRANIAL CRESTS IN BUFO MARMOREUS AND B. PERPLEXUS.

+------------------------+---+-----------+------------+----------+ |LOCALITY | N | Curved |Intermediate| Angular | +------------------------+---+-----------+------------+----------+ |Tepalcatepec Valley | 50| 10 (20.0%)| 17 (34.0%) |23 (46.0%)| +------------------------+---+-----------+------------+----------+ |Morelos | 12| 2 (16.6%)| 5 (41.7%) | 5 (41.7%)| +------------------------+---+-----------+------------+----------+ |Izucar, Puebla | 4| 2 (50.0%)| 0 (0.0%) | 2 (50.0%)| +------------------------+---+-----------+------------+----------+ |Southern Sinaloa | 1| 1(100.0%)| 0 (0.0%) | 0 (0.0%)| +------------------------+---+-----------+------------+----------+ |Puerto Vallarta, Jalisco| 2| 2(100.0%)| 0 (0.0%) | 0 (0.0%)| +------------------------+---+-----------+------------+----------+ |Colima | 45| 25 (55.0%)| 18 (40.0%) | 2 (5.0%)| +------------------------+---+-----------+------------+----------+ |Coast of Michoacan | 55| 35 (63.6%)| 17 (30.9%) | 3 (5.5%)| +------------------------+---+-----------+------------+----------+ |Acapulco, Guerrero | 7| 7(100.0%)| 0 (0.0%) | 0 (0.0%)| +------------------------+---+-----------+------------+----------+ |Chilpancingo, Guerrero | 10| 1 (10.0%)| 4 (40.0%) | 5 (50.0%)| +------------------------+---+-----------+------------+----------+ |Pochutla, Oaxaca | 13| 6 (46.2%)| 6 (46.2%) | 1 (7.6%)| +------------------------+---+-----------+------------+----------+ |Tehuantepec, Oaxaca |177| 81 (45.8%)| 67 (37.8%) |29 (16.4%)| +------------------------+---+-----------+------------+----------+ |Tonola, Chiapas | 1| 0 (0.0%)| 0 (0.0%) | 1(100.0%)| +------------------------+---+-----------+------------+----------+ |Veracruz | 33| 26 (78.8%)| 6 (18.2%) | 1 (3.0%)| +------------------------+---+-----------+------------+----------+ | Total |410|198 (48.3%)|140 (34.2%) |72 (17.5%)| +------------------------+---+-----------+------------+----------+

1. Although the highest percentage of individuals having the
supraorbital and postorbital crests forming a sharp angle is
from localities in the Balsas-Tepalcatepec Basin, numerous
individuals from throughout the range of _marmoreus_ have the
crests forming an angle (Table 1).

2. In all samples of ten or more specimens, some toads have
the supraorbital and postorbital crests forming a sharp
angle, some have the crests forming a curve, and some have
an intermediate condition.

3. The relative size of the supratympanic crest is highly
variable in all samples examined.

Hatchling of _Pseudoeurycea belli_ from San Juan de Parangaricutiro, Michoacan. x 8.]

FIG. 1. Nest and eggs of _Pseudoeurycea belli_ beneath a rock at San Juan de Parangaricutiro. Approx. natural size.

FIG. 2. Multiple egg clutches of _Phyllomedusa dacnicolor_ from Coalcoman, Michoacan. 1/3 x.

FIG. 1. Adult male of _Tomodactylus angustidigitorum_ from Paracho, Michoacan. x 4.

FIG. 2. Adult male of _Tomodactylus fuscus_ from Los Cantiles, Michoacan. x4.

FIG. 1. Adult male of _Tomodactylus nitidus_ nitidus from Tuxpan, Michoacan. x.

FIG. 2. Adult male of _Tomodactylus nitidus orarius_ from Tecolapa, Colima. x 4.]

FIG. 1. Adult male of _Tomodactylus nitidus_ petersi from Apatzingan, Michoacan. x 4.

Fig. 2. Adult male of _Tomodactylus rufescens_ from Dos Aguas, Michoacan. x 4.]

FIG. 1. Adult male of _Hypopachus caprimimus_ from Tuxpan, Michoacan. x 2-1/2.

FIG. 2. Adult male of _Hypopachus oxyrrhinus ovis_ from Tangamandapio, Michoacan. x 3.]

4. A distinct, pale-colored, diagonal lateral stripe is
found in females only from localities outside of the
Balsas-Tepalcatepec Basin; females from the basin have a
spotted dorsum.

5. Males from the Balsas-Tepalcatepec Basin usually have a
broad middorsal line that is yellow or pale tan; those from
outside the basin have either a narrow middorsal line or
none.

6. Males from the Balsas-Tepalcatepec Basin have low,
scattered dorsal tubercles (Fig. 3); males from outside the
basin have a concentration of tubercles in a broad band on
the back (Fig. 4).

Therefore the nature of the cranial crests is of little value in separating two populations, but the color pattern of the females and the nature of the dorsal tubercles of the males do show distinct differences. Furthermore, certain differences in size and proportion are evident; _Bufo marmoreus_ is a slightly larger toad and has a relatively longer tibia and longer head than _perplexus_ (Table 2).

TABLE 2.--COMPARISON OF CERTAIN MEASUREMENTS AND PROPORTIONS IN BUFO MARMOREUS AND B. PERPLEXUS. (MEANS ARE GIVEN IN PARENTHESES BELOW THE RANGES.)

+-------------------+------------+--+----------+------------+-----------+ | | | | |Tibia length|Head length| | Species | Sex | N|Snout-vent+------------+-----------+ | | | | length | Snout-vent |Snout-vent | | | | | | length | length | +-------------------+------------+--+----------+------------+-----------+ | _B. marmoreus_ | Male |15|61.5-72.5 | 35.9-41.6 | 28.3-33.3 | | | | | (65.2) | (39.0) | (31.6) | +-------------------+------------+--+----------+------------+-----------+ | _B. perplexus_ | Male |20|50.0-59.0 | 33.7-38.1 | 26.4-31.1 | | | | | (54.9) | (36.4) | (29.5) | +-------------------+------------+--+----------+------------+-----------+ | _B. marmoreus_ | Female | 7|68.0-76.0 | 33.0-36.8 | 26.8-32.6 | | | | | (70.7) | (34.7) | (29.6) | +-------------------+------------+--+----------+------------+-----------+ | _B. perplexus_ |Female | 6|64.1-69.8 | 32.4-36.9 | 25.1-29.0 | | | | | (66.8) | (35.5) | (27.5) | +-------------------+------------+--+----------+------------+-----------+