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.

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) | +-------------------+------------+--+----------+------------+-----------+

Taylor (1943a:347) described _Bufo perplexus_ from Mexcala on the Rio Balsas in Guerrero. Among the many paratypes are specimens from Tonola, Chiapas, and Tehuantepec, Oaxaca. These apparently were referred to _perplexus_ solely on the nature of the cranial crests. All of the specimens examined during the course of the present study from the lowlands of Veracruz and from the Pacific lowlands from Sinaloa southward to Chiapas are referable to _Bufo marmoreus_; those from the Balsas-Tepalcatepec Basin are referable to _Bufo perplexus_, as defined above. Ten specimens from Chilpancingo, Guerrero (UMMZ 115352), do not readily fit either species. Perhaps there is gene exchange between the inland and coastal populations through the relatively low pass at Chilpancingo, at the mouth of the Rio Balsas, and near the convergent headwaters of the Rio Coahuayana and Rio Tepalcatepec in southern Jalisco. If this can be demonstrated, then _Bufo perplexus_ would have to be considered as a subspecies of _Bufo marmoreus_, instead of an allopatric species.

~Bufo perplexus~ Taylor

_Bufo perplexus_ Taylor, Univ. Kansas Sci. Bull., 29:347, October 15, 1943.--Balsas River near Mexcala, Guerrero, Mexico.

Aguililla (2); Apatzingan (42); Buena Vista (5); Capirio (3); La Playa (25); Lombardia (6); Nueva Italia (9); Rio Cancita, 14 km. E of Apatzingan; Rio Tepalcatepec, 27 km. S of Apatzingan; San Salvador (4); Tzitzio; Volcan Jorullo.

~Bufo occidentalis~ Camerano

_Bufo occidentalis_ Camerano, Atti R. Accad. Sci. Torino, 14:887, December 31, 1878.--Mexico. Type locality restricted to Guanajuato, Guanajuato, Mexico, by Smith and Taylor (1950a:330). Firschein, Copeia, no. 3:220, September 15, 1950.

_Bufo simus_, Smith and Taylor, Bull. U. S. Natl. Mus., 194:42, 1948.

Barranca Seca (32); Cerro de Barolosa (4); Cerro Tancitaro, 3 km. E of Apo (2); Cerro Tancitaro, 19 km. E. of Apo (10); Charapendo; Coalcoman (7); Dos Aguas (4); Jacona, Jaramillo (2); Las Tecatas; Los Reyes (181); Tancitaro (10); Uruapan (3).

This toad is an inhabitant of pine and oak forests between 900 and 2400 meters. Near Charapendo on the slopes of the Sierra de los Tarascos and at Coalcoman it apparently reaches its lowest altitudinal limits. At both of these localities the pine-oak forest is replaced by arid tropical scrub forest on the lower slopes.

Twenty-four tadpoles were collected on May 3 in a quiet section of a fast stream near Barranca Seca. The tadpoles have a robust body, broadest about two-thirds the distance from the snout to the posterior edge of the body, half again as broad as deep. Eyes dorsolateral; nostrils dorsal, somewhat directed forward, and about three-fifths the distance from the tip of the snout to the eye; spiracle sinistral and lateral, located at about midbody; anus median; tail long and slender; tail-musculature extends nearly to tip of tail; depth of tail-musculature at mid-length about one-third total depth of tail; dorsal tail-fin not extending onto body (Fig. 5); average body length of ten tadpoles having small hind limb buds, 14.4 mm.; average tail length, 22.0 mm.

Mouth ventral, nearly terminal, about one-third as wide as widest part of body; anterior lip has no papillae; lower lip bordered by two rows of papillae and lateral lips by one row of papillae; beaks moderately well developed, the upper forming a broad arch and finely denticulate; tooth rows 2/3, the upper rows extending to the edge of the lips, subequal in length, and slightly longer than lower rows, which also are subequal in length; inner upper tooth row broken medially; inner lower tooth row sometimes broken (Fig. 6).

The body is black dorsally and laterally, and bluish gray ventrally; the tail musculature is brown and stippled with darker brown. The fins are transparent and stippled with brown, the stippling being most pronounced on the posterior two-thirds of the upper tail-fin.

Forty recently metamorphosed individuals average 18.9 mm. in snout-vent length.

The relationships of this toad seem to be with _Bufo bocourti_ Brocchi, an inhabitant of pine and oak forests in the uplands of Chiapas and Guatemala. In _Bufo occidentalis_ the tympanum usually is indistinct and sometimes completely covered, and it is absent in _bocourti_. _Bufo occidentalis_ has a broader interorbital area and relatively shorter and more rounded parotid glands than _bocourti_. The tadpoles of the two species are nearly identical (see Stuart, 1943:12).

~Leptodactylus labialis~ (Cope)

_Cystignathus labialis_ Cope, Proc. Amer. Philos. Soc., 17:90, 1877.--No type locality designated; type locality restricted to Potrero Viejo, Veracruz, Mexico, by Smith and Taylor (1950a:350).

_Leptodactylus labialis_, Brocchi, Mission Scientifique au Mexique et dans l'Amerique Centrale, pt. 3, sec. 2, livr. 1:20, 1881.

Apatzingan (26); Capirio (5); Cofradia (9); El Sabino (4); Lombardia; Rio Tepalcatepec, 27 km. S of Apatzingan (2).

In the Tepalcatepec Valley this frog reaches the northernmost known limit of its range in western Mexico. Although the species is abundant in the valley, it apparently is absent from the coastal lowlands. In the Tepalcatepec Valley _Leptodactylus melanonotus_ seems to be more abundant than _labialis_. In the rainy season both species have been heard calling from the same ponds and flooded fields.

There are only slight differences in size between the sexes; measurements of 20 males and eight females are, respectively: snout-vent length, 32.3-39.5 (35.1), 34.1-39.2 (37.2); tibia length, 14.3-17.0 (15.4), 14.9-16.8 (15.8); head width, 11.0-13.6 (12.0), 12.2-13.2 (12.6); head length, 12.8-15.1 (13.3), 12.8-14.6 (13.7).

~Leptodactylus melanonotus~ (Hallowell)

_Cystignathus melanonotus_ Hallowell, Proc. Acad. Nat. Sci. Philadelphia, 12:485, 1861.--Nicaragua. Type locality restricted to Recero, Nicaragua, by Smith and Taylor (1950a:320).

_Leptodactylus melanonotus_, Brocchi, Mission Scientifique au Mexique et dans l'Amerique Centrale, pt. 3, sec. 2, livr. 1:20, 1881.

Apatzingan (103); Capirio; Charapendo (7); Coahuayana; Cofradia (10); El Sabino (21); La Playa (3); Lombardia (5); Maruata; Nueva Italia (7); Ostula (9); Playa Azul (11); Rio Marquez, 10 km. S of Lombardia; Rio Marquez, 13 km. SE of Nueva Italia (6); Rio Tepalcatepec, 27 km. S of Apatzingan.

This species is widespread in the lowlands of the state; it has been collected up to elevations of 1050 meters in the Tepalcatepec Valley. In the dry season individuals were discovered beneath rocks along streams and in damp arroyos; in the rainy season they were found wherever there was water. Males were heard calling from flooded fields, ditches, rocky streams, and small puddles. The call is a series of individual notes: "woink, woink, woink."

Adult males are noticeably smaller than females; measurements for 20 males and ten females from Apatzingan are, respectively: snout-vent length, 29.6-34.6 (32.3), 36.3-44.1 (40.8); tibia length, 12.6-15.1 (14.0), 16.5-19.0 (17.8); head width, 10.8-11.9 (11.3), 12.6-14.8 (13.7); head length, 11.2-13.2 (11.9), 13.1-14.8 (14.0). Brownish yellow ventral glands are present in some juveniles and in some adults collected in the dry season as well as in the rainy season.

~Leptodactylus occidentalis~ Taylor

_Leptodactylus occidentalis_ Taylor, Trans. Kansas Acad. Sci., 39:349, 1937.--Tepic, Nayarit, Mexico.

Five km. W of Tangamandapio.

On the night of June 11, 1958, this species was calling from a hyacinth-choked ditch. Although numerous individuals were heard, only one specimen was obtained. The frogs were calling from the tangled mat of hyacinths along with _Hyla eximia_, _Hypopachus oxyrrhinus ovis_, and _Rana pipiens_.

Taylor (1936a:352) characterized this species as follows: "The narrow head, small maximum size (38 mm. for females, 33 mm. for males), the character of the postaxillary and postfemoral glands, the narrower groups of vomerine teeth, clearly distinguish this western Mexican form from the more robust, larger _melanonotus_ to the south. The call is likewise fainter and different in quality." Concerning the glands, Taylor (_loc. cit._) remarked: "There is a possibility that the horny excrescence covering the glands may appear only during the breeding season. This character is quite as strongly marked in females as in males." Bogert and Oliver (1945:324) concluded that the population of _Leptodactylus_ in northwestern Mexico could not be distinguished from _melanonotus_ in other parts of the country and thus synonymized _Leptodactylus occidentalis_ with _melanonotus_. Bogert and Oliver (op. cit.: 324) stated that the extent as well as the presence or absence of ventral glands was highly variable in all samples examined by them.

Upon seeing numerous living individuals of _Leptodactylus melanonotus_ from many parts of its range in Mexico and individuals of the population of _Leptodactylus_ in northwestern Mexico (Nayarit and Sinaloa), I was immediately impressed not so much by the differences in the development of the ventral glands, but by the color of the glands. The differences in color are apparent in freshly preserved specimens. With the exception of _Leptodactylus_ from northwestern Mexico, specimens of _melanonotus_ from throughout Mexico and northern Central America have yellow or yellowish brown glands. Specimens from northwestern Mexico have black or brownish black glands that are conspicuously darker than those found in _melanonotus_. Examination of 653 preserved specimens of _Leptodactylus melanonotus_ from Mexico and Guatemala has failed to reveal specimens with black ventral glands, like those found in specimens from northwestern Mexico, to which the name _Leptodactylus occidentalis_ has been applied. Furthermore, in _melanonotus_ the glands are less distinct and more extensive than in _occidentalis_; in the latter species glands are absent from the throat and midventral area, where they often are present in _melanonotus_ (Fig. 7).

In some individuals of both species collected in the dry season and in some collected in the rainy (breeding) season the glands are absent; the development of these glands, therefore, does not seem to be correlated with breeding. Likewise, the glands are present or absent in either sex, and often as not they are present in juveniles. Presence of the glands, therefore, cannot be correlated either with sexual or ontogenetic development. Since the glands are found in individuals from all parts of the range, it is unlikely that there is a correlation between the development of the glands and the environment.

Aside from the differences in the ventral glands, the call is different in the two populations. The call of _Leptodactylus occidentalis_ is a rather harsh "wack, wack, wack" as contrasted with the more nasal "woink, woink, woink" of _melanonotus_. Sound spectrographs are needed to analyze the differences in calls. None of the specimens of _occidentalis_ examined approaches in size the largest individuals of _melanonotus_; possibly the size of the frogs is another valid character for separating the species. On the basis of the above data it is evident that the frogs in northwestern Mexico show certain characters that distinguish them from _Leptodactylus melanonotus_, as it is known throughout the rest of Mexico. It is not known for certain that _melanonotus_ and _occidentalis_ are sympatric. Several series of old, poorly preserved specimens from Nayarit and Sinaloa cannot be placed in either species, for none has visible ventral glands. _Leptodactylus melanonotus_ is known from Acaponeta, Nayarit (AMNH 43913-25), and the following localities in Jalisco: Barro de Navidad (UMMZ 118098), La Concepcion (UMMZ 113081), La Resolana (UMMZ 102104), and Tenachitlan (UMMZ 113045-6). Records for _Leptodactylus occidentalis_ are: Alamos, Sonora (AMNH 51356-65); Culiacan (AMNH 49511-9), Chele (UMMZ 110914), and Rosario (UMMZ 113062) in Sinaloa; Ixtlan del Rio (UMMZ 102108), San Blas (UMMZ 112814, 112994, 110892, 115543), and Tepic (UMMZ 115544) in Nayarit; Ameca (UMMZ 102106-7) and La Cofradia on the south shore of Lago de Chapala (UMMZ 102105) in Jalisco; and Tangamandapio, Michoacan (UMMZ 119145). From these scattered records it appears that _Leptodactylus occidentalis_ in the southern part of its range stays in the uplands, whereas _melanonotus_ is confined to the lowlands.

~Microbatrachylus hobartsmithi~ (Taylor)

_Eleutherodactylus hobartsmithi_ Taylor, Trans. Kansas Acad. Sci., 39:355, 1937.--Uruapan, Michoacan, Mexico.

_Microbatrachylus hobartsmithi_ Taylor, Univ. Kansas Sci. Bull., 26:501, November 27, 1940.

Cascada Tzararacua (6); 21 km. W of Ciudad Hidalgo; 29 km. E of Morelia; Puerto Hondo; San Jose de la Cumbre (13); Uruapan (2); Zitacuaro.

Of six specimens from Cascada Tzararacua, five are colored like typical _M. hobartsmithi_, having the anterior and posterior surfaces of the thighs and the upper arms pale pink in life and a grayish brown dorsum in preservative. The other specimen (UMMZ 94231) has in preservative a dark brown dorsolateral line on each side enclosing a pale tan area that extends from the snout to the vent. One specimen from 29 kilometers east of Morelia (UIMNH 40338) and 13 specimens from San Jose de la Cumbre (UMMZ 102111) do not have the prominent tarsal tubercles characteristic of _M. hobartsmithi_. Also, in these fourteen specimens the palmar tubercles are larger, and the dark anal patch more distinct, than in typical _M. hobartsmithi_. Possibly these specimens, which are from the high mountains in the eastern part of Michoacan, represent another species of _Microbatrachylus_. However, Taylor (1940d:501) reported a series of _M. hobartsmithi_ from the mountains 10 miles west of Villa Victoria in the western part of the state of Mexico.

The largest specimen from Michoacan is a gravid female (UIMNH 16104) having a snout-vent length of 23.5 mm.

_Microbatrachylus hobartsmithi_ has been found in rocky ravines along streams in the Cordillera Volcanica and the southwestern escarpment of these mountains at elevations from 1450 to 2750 meters.

~Microbatrachylus pygmaeus~ (Taylor)

_Eleutherodactylus pygmaeus_ Taylor, Trans. Kansas Acad. Sci., 39:352, 1937.--1 mile north of Rodriguez Clara, Veracruz, Mexico.

_Microbatrachylus pygmaeus_ Taylor, Univ. Kansas Sci. Bull., 26:500, November 27, 1940.

_Microbatrachylus albolabris_ Taylor, Univ. Kansas Sci. Bull., 26:502, November 27, 1940.--2 miles west of Cordoba, Veracruz, Mexico.

_Microbatrachylus minimus_ Taylor, Univ. Kansas Sci. Bull., 26:507, November 27, 1940.--Agua del Obispo, Guerrero, Mexico.

_Microbatrachylus imitator_ Taylor, Univ. Kansas Sci. Bull., 28:70, May 15, 1942.--La Esperanza, Chiapas, Mexico.

Arteaga (328).

This large series (UMMZ 119247-8) was collected on June 22 and 23, 1958, before the onset of the heavy summer rains. The frogs were found in a shaded ravine at the north edge of Arteaga; they were obtained during the day, at which time they were actively moving about in the leaf litter along a small stream.

These frogs are all referred to _M. pygmaeus_, because this is the earliest name available for frogs showing the variation in characteristics displayed by this large series. The characters used by Taylor (1936a, 1940d, 1941a, and 1942b) and Smith and Taylor (1948) to distinguish the various species of _Microbatrachylus_ include color pattern, relative length of the hind limb, presence and position of dorsal dermal folds or pustules, relative size of inner and outer metatarsal tubercles, and the number of palmar tubercles. All specimens from Arteaga have two palmar tubercles; the inner and outer metatarsal tubercles are subequal in size. Furthermore, aside from sexual difference, there is little variation in the relative length of the hind limbs (Table 3). However, many color patterns do exist in the series; each of these color patterns is described below.

TABLE 3.--SNOUT-VENT LENGTH EXPRESSED AS A PERCENTAGE OF TIBIA LENGTH IN ANIMALS OF SIX COLOR PATTERNS OF MICROBATRACHYLUS PYGMAEUS. (LETTERS REFER TO THE VARIANTS HAVING THE COLOR PATTERN DISCUSSED IMMEDIATELY BELOW)

+------------+-----------+---------+---------+----+--------+ | | | Number | Range | | Twice | | Color | Sex | of | of |Mean|standard| |Pattern | |specimens|variation| | error | | | | | | |of mean | +------------+-----------+---------+---------+----+--------+ | A | Male | 25 |51.4-57.5|55.2| 3.34 | | | Female | 25 |49.3-54.9|51.6| 3.12 | | B | Male | 20 |51.0-57.1|55.4| 2.44 | | | Female | 21 |47.3-54.9|51.2| 3.52 | | C | Male | 6 |54.5-56.2|55.2| .... | | | Female | 6 |50.0-52.9|51.6| .... | | D | Male | 17 |52.9-58.2|55.4| 2.64 | | | Female | 14 |48.5-56.6|52.1| 4.16 | | E | Male | 10 |50.9-56.9|55.1| 3.40 | | | Female | 7 |49.6-54.5|51.6| .... | | F | Female | 2 |51.9-52.6|52.3| .... | +------------+-----------+---------+---------+----+--------+

A.--225 specimens: Dorsum mottled brown and cream, usually with a dark spot between the eyes and one or two dark V-shaped marks with the apex anteriorly on the back; 55 of these have a narrow cream-colored line from the tip of the snout to the vent and thence onto the posterior surfaces of the thighs. All are pustulate above; in most specimens the pustules form no pattern, but in some they tend to form a V in the scapular region.

B.--41 specimens: Dorsum pale tan or cream-color with brown mottling on flanks; a brown interorbital bar and a brown chevron in scapular region. Dorsum irregularly pustulate; in some specimens the pustules tend to form a V in the scapular region.

C.--12 specimens: Dorsum colored like "A", but having a broad yellow stripe narrowly bordered by black from the tip of the snout to the vent; in some specimens there is a narrow yellow stripe on the posterior surfaces of the thighs. The dorsum is irregularly pustulate.

D.--31 specimens: Dorsum variably streaked with cream-color or pale tan and brown; usually a broad cream-colored stripe from eyelid to groin bordered laterally by a somewhat narrower brown stripe; middorsal area cream-color and separated from dorsolateral cream-colored stripe by a brown stripe, or middorsal area brown with a cream-colored or yellow, narrow stripe from tip of snout to vent; a dark stripe from tympanum to flank; dorsal surfaces of heels creamy white to pale orange; anal patch brown. A dermal ridge from posterior edge of eyelid to rump; another ridge extends posteromedially from the eyelid; scattered pustules on the dorsum in some specimens.

E.--17 specimens: A narrow dark stripe from snout, through nostril and eye, over tympanum, to vent, enclosing a unicolor dorsum (reddish tan to yellowish tan in life); heels pale tan or yellow above; anal patch black. A faint dermal ridge from posterior edge of eyelid to rump, or part way to rump.

F.--2 specimens: Mottled brown and cream-color above; upper lips and upper arms white. A dermal fold from posterior edge of eyelid to rump; scattered pustules on dorsum.

Some of these color variants are assignable to names proposed by Taylor: "A" and "B" undoubtedly are _M. pygmaeus_ (Taylor, 1936a); "C" probably is _M. pygmaeus_; "D" is referable to _M. minimus_ (Taylor, 1940d) in most characteristics, although the coloration is more nearly like that of _M. lineatissimus_ (Taylor, 1941a), a larger species characterized by a relatively long hind limb; "E" apparently is _M. imitator_ (Taylor, 1942b); "F" is _M. albolabris_ (Taylor, 1940d). Examination of series of these frogs from other parts of Mexico shows a similar composition of color variants. Of 78 specimens from the Rio Sarabia and the village of Sarabia in Oaxaca (UMMZ 115428-37), 57 are "A," six are "D," three are "E," and 12 are "F"; of 22 specimens from Teapa, Tabasco (UMMZ 113829), 11 are "A," five are "D," two are "E," and four are "F"; of 33 specimens from Potrero Viejo, Veracruz (USNM 115447-58, 115461-71, 116840-2, 116864-70), ten are "A," 13 are "E," and ten are "F"; of 31 specimens from La Esperanza, Chiapas (USNM 115477-9, 116827-39, 116849-63), 28 are "A" and four are "F."

It is highly doubtful if these color variants are actually distinct species. Goin (1950 and 1954) in his studies of inheritance of color pattern in West Indian species of the genus _Eleutherodactylus_ has shown that similar color pattern variants come from the same clutch of eggs; furthermore, Goin has worked out the genetic ratios of certain of these variants. Heathwole (_in litt._) obtained "normal" specimens and individuals having a broad middorsal stripe ("C" in figure 9) from a clutch of eggs of _Eleutherodactylus gollmeri_. The presence of a broad middorsal yellow stripe is common in _Eleutherodactylus rugulosus_.

Perhaps the most interesting aspect of variability in color pattern in Mexican eleutherodactylids is the parallelism between members of the _Eleutherodactylus rhodopis_-group and some members of _Microbatrachylus_. In the former group there are white-lipped individuals (_Eleutherodactylus beatae_ Boulenger), individuals having a unicolor reddish or yellowish dorsum (_E. dorsoconcolor_ Taylor), and individuals having a dorsal pattern of irregular longitudinal brown and cream-colored streaks (_E. venustus_ Guenther). In the humid forests of southern Veracruz, northern Oaxaca, and Chiapas members of both groups occur sympatrically. A proper understanding of the evolutionary significance of these variants in the two groups, as well as proper allocation of the presently recognized species, must await experimental evidence based on studies of the inheritance of color pattern. Nevertheless, at present it is apparent that certain characters, especially the nature of the dermal folds and pustules, and the color pattern, are of little taxonomic value in distinguishing "species" of _Microbatrachylus_. The data derived from a study of the large series from Arteaga, together with that from the other series examined, suggests that _Microbatrachylus albolabris_, _imitator_, _minimus_, and _pygmaeus_ are morphotypes of one species. Of these names, _pygmaeus_ is the oldest. Consequently _Microbatrachylus pygmaeus_ has been used here for the series from Arteaga.

Although _Microbatrachylus hobartsmithi_, a species distinguished from all of the above by the presence of tubercles on the outer edge of the tarsus, is known from Michoacan northward into Nayarit, _Microbatrachylus pygmaeus_ previously has not been known north of Guerrero, where it occurs in habitats similar to that in which it was collected at Arteaga.

~Eleutherodactylus augusti cactorum~ Taylor

_Eleutherodactylus cactorum_ Taylor, Univ. Kansas Sci. Bull., 25:391, July 10, 1939.--20 miles northwest of Tehuacan, Puebla, Mexico.

_Eleutherodactylus augusti cactorum_, Zweifel, Amer. Mus. Novitates, 1813:20, December 23, 1956.

Cheran; Coalcoman; Uruapan.

The few specimens indicate that this species occurs at moderate to high elevations in the state. The specimens from Cheran and Uruapan were obtained in pine forests; the specimen from Coalcoman was found on a rocky hillside covered with dense forest and located about 100 meters below the lower limits of the pine forest in the area. A specimen from Rancho Reparto (elevation 1850 meters) on the west slope of Cerro Barolosa was lost.

The specimen from Coalcoman (UMMZ 104728) is a juvenile having a snout-vent length of 25.0 mm. In life it was tan above, mottled with olive-green. The ventral surfaces were gray; the hind limbs were distinctly barred with yellow and brown, and the lips were barred with yellow and black.

~Eleutherodactylus occidentalis~ Taylor

_Eleutherodactylus occidentalis_ Taylor, Proc. Biol. Soc. Washington, 54:91, July 31, 1941.--Hacienda El Florencio, Zacatecas, Mexico.

Arteaga (2); Cascada Tzararacua; Coalcoman (2); 19 km. SW of Coire (3); La Placita (7); Los Reyes; Ostula (4); Pomaro (2).

The locality records for this species suggest that it is a member of a group of animals, the distribution of which includes the western part of the Mexican Plateau and the Pacific lowlands. In Michoacan this frog has been collected in pine-oak forest at Cascada Tzararacua and at Los Reyes, in arid scrub forest at Arteaga and Coalcoman, and in tropical semi-deciduous forest on the lower Pacific slopes of the Sierra de Coalcoman. On July 5, 1950, James Peters (1954:6) found calling males at La Placita.

Most of the specimens are immature; four adult males have snout-vent lengths of 30.9-33.0 (32.2) mm. In all specimens the first finger is noticeably longer than the second; the inner metatarsal tubercle is large, flat, and cream-colored, contrasting with the dark brown sole of the foot. When the hind limbs are adpressed, the heels broadly overlap. Characteristically, a dark line extends from the snout, through the eye, above the tympanum, to a point above the insertion of the forelimb. Usually there is a dark bar behind the tympanum, two dark brown bars from the eye to the mouth and thence onto the lower jaw, and another dark bar on the upper lip between the eye and nostril. One adult from Arteaga, an adult and a juvenile from La Placita, and one juvenile each from Coire, Ostula, and Pomaro, have the lower lip barred with dark brown and white, and have a white stripe extending the length of the upper lip. In life the dorsum varies from dark gray or olive-brown to tan or reddish brown.

This species belongs to a group containing two other populations that are currently recognized as species--_calcitrans_, known only from Omiltemi, Guerrero, and _mexicanus_, reported from the mountains of Oaxaca. Another apparently undescribed member of this group has been collected in the mountains of northern Puebla. The locality records indicate that the group inhabits the mountains on the periphery of the Mexican Plateau, except in western Mexico, where _Eleutherodactylus occidentalis_ extends to the Pacific lowlands.

~Eleutherodactylus rugulosus vocalis~ Taylor

_Eleutherodactylus vocalis_ Taylor, Univ. Kansas Sci. Bull., 26:401, November 27, 1940.--Hacienda El Sabino, Michoacan, Mexico.

Arteaga (10); El Sabino (8); Salitre de Estopilas (3); Tumbiscatio (2); Tzitzio (2).

The distributional data on this frog in Michoacan indicate that it inhabits riparian situations in arroyos and canyons in the lower slopes of the Cordillera Volcanica and the Sierra de Coalcoman, where it has been taken at elevations only below 1100 meters.

The dorsal color of living individuals from Arteaga varied from dark gray and olive brown to tan and reddish brown. The iris was grayish brown. In contrast, individuals from Agua del Obispo, Guerrero, had pale golden eyes; specimens from Matias Romero, Oaxaca, had gold eyes heavily flecked with gray; and individuals from Volcan San Martin, Veracruz, had bronze eyes.

The use of the trinomial here is arbitrary. Frogs of the _Eleutherodactylus rugulosus_ group in Mexico (_rugulosus_, _avocalis_, and _vocalis_) exhibit only slight differences in size, proportions, and coloration (Duellman, 1958c:6). Furthermore, the named populations are allopatric. _Eleutherodactylus rugulosus vocalis_, as defined by Duellman (_loc. cit._), occurs in the foothills of the Sierra Madre Occidental and associated ranges from central Sinaloa southward into Michoacan.

~Tomodactylus angustidigitorum~ Taylor

_Tomadactylus angustidigitorum_ Taylor, Univ. Kansas Sci. Bull., 26:494, November 27, 1940.--Quiroga, Michoacan, Mexico.

Angahuan (6); Apo; Carapan (21); 19 km. S of Carapan (13); Cerro Tancitaro (12); Cheran; Corupu (14); Cuseno Station (14); Opopeo (3); Paracho (11); Paricutin (2); Patzcuaro (3); Quiroga (59); San Juan de Parangaricutiro (16); Tancitaro (25); Uruapan (8); Zacapu (11).

This species is indigenous to the pine-oak forests on the southern rim of the Mexican Plateau, and has been collected at elevations from 1500 to 2500 meters. Males have been observed to call from rocks, rock fences, clumps of grass, and low bushes; the call is a single "peep." At San Juan de Parangaricutiro numerous specimens were found in the daytime beneath adobe bricks and lava on the volcanic ash derived from Volcan Paricutin; at Paracho individuals were found by day beneath rocks in a pine forest.

In most specimens the dorsum is dark reddish brown, and the prominent inguinal glands are cream-color or pale orange (Pl. 3, Fig. 1). Of eight individuals collected at Paracho, one was reddish brown, two were pinkish tan, three were dark brown, and two were black.

~Tomodactylus fuscus~ Davis and Dixon

_Tomodactylus fuscus_ Davis and Dixon, Herpetologica, 11:157, July 15, 1955.--1.5 miles southeast of Huitzilac, Morelos, Mexico.

Los Cantiles (2); 28 km. E of Morelia.

The range of this species includes the Sierra Ajusco in Mexico and Morelos and thence westward to the Serrania Ucareo in Michoacan. The specimen from 28 kilometers east of Morelia was found in an oak forest on a steep hillside at an elevation of 2100 meters. One from Los Cantiles was calling from a steep cliff at an elevation of 2200 meters in pine-oak forest. This specimen (UMMZ 119156) in life had a pale olive-brown dorsum with irregular dark brown mottling and transverse bars on the limbs. The interorbital bar, the upper arms, and the tips of the dorsal pustules were pale orange; the iris was pale grayish gold (Pl. 3, Fig. 2).

~Tomodactylus nitidus nitidus~ (Peters)

_Liuperus nitidus_ Peters, Monats. Akad. Wiss. Berlin, p. 878, 1869.--Izucar de Matamoras, Puebla, Mexico.

_Tomodactylus amulae_ Guenther, Biologia Centrali-Americana, Reptilia and Batrachia, p. 219, April, 1900.--Amula, Guerrero, Mexico.

_Tomodactylus nitidus nitidus_, Dixon, Texas Jour. Sci., 9:385, December, 1957.

Copuyo (15); Tuxpan (8); Tzitzio (11).

One specimen from Tzitzio (UMMZ 99155) was referred to _Tomodactylus nitidus petersi_ by Dixon (1957:390). A re-examination of this specimen, and examination of ten others from the same locality (UMMZ 121571) reveals that the relatively small size of the tympanum and absence of dense ventral spotting place these specimens closer to _T. nitidus nitidus_ than to _T. nitidus petersi_.

The specimens from Tuxpan (UMMZ 114303-4) had in life a gray to olive tan ground color with dark olive-green markings, bright yellow thighs with olive-green transverse bands, yellowish tan shanks with olive-green bars, yellow groin, white inguinal glands with black markings, grayish white belly with scattered brownish black spots in some specimens, and a deep golden iris (Pl. 4, Fig. 1). These specimens were found calling from bushes in a rocky field at an elevation of 1800 meters. The call is a high-pitched "pee-ee-eep."

~Tomodactylus nitidus orarius~ Dixon

_Tomodactylus nitidus orarius_ Dixon, Texas Jour. Sci., 9:392, December, 1957.--4.5 miles southwest of Tecolapa, Colima, Mexico.

La Placita (3); Pomaro.

These specimens, referred to _Tomodactylus petersi_ by Duellman (1954b:5), were included in _T. nitidus orarius_ by Dixon (1957:392). Color notes based on living individuals from Tecolapa, Colima (UMMZ 114312 and 116922), are: gray above mottled with brown; venter dirty white; anterior and posterior surfaces of thighs bright yellow; iris pale golden (Pl. 4, Fig. 2). The call is a soft "braa" usually followed by three high notes: "braaa-eep-ee-eep." In Michoacan this subspecies has been found only in the coastal region and the lower foothills of the Sierra de Coalcoman, an area in which it replaces _Tomodactylus nitidus petersi_. This is the only _Tomodactylus_ known to inhabit coastal lowlands.

~Tomodactylus nitidus petersi~ Duellman

_Tomodactylus petersi_ Duellman, Occ. Pap. Mus. Zool. Univ. Michigan, 560:5, October 22, 1954.--Coalcoman, Michoacan, Mexico.

_Tomodactylus nitidus petersi_, Dixon, Texas Jour. Sci., 9:390, December, 1957.

Aguililla; Apatzingan (8); Cascada Tzararacua: Charapendo (5); Coalcoman (5); 18 km. E of Dos Aguas (6); El Sabino (5); La Playa (2); Jiquilpan; Uruapan (2); Volcan Jorullo; Zamora.

In life, specimens from Apatzingan (UMMZ 114308-9) varied in dorsal color from grayish tan to pale brown; the dorsal markings were olive green. The thighs and groin were yellowish orange; the iris was pale golden, and the vocal sac was purplish gray (Pl. 5, Fig. 1). Measurements for 13 adult males from the Tepalcatepec Valley are: snout-vent length, 21.9-26.8 (24.3); tibia length, 8.4-9.9 (9.3); head width, 7.2-9.2 (7.8); head length, 7.6-8.7 (8.2).

At Apatzingan and Charapendo in the Tepalcatepec Valley males were found calling from rocks and bushes in open arid tropical scrub forest. The call, a triple note "peep-ee-eep," is repeated once every 90 to 135 seconds. _Tomodactylus nitidus petersi_ probably ranges throughout the Tepalcatepec Valley and surrounding foothills. Dixon (1957:392) referred the specimens from Zamora, Jiquilpan, and Uruapan to this subspecies. Uruapan is near the lower limits of the pine forest on the slopes of the Cordillera Volcanica; Zamora and Jiquilpan are on a low part of the Mexican Plateau southeast of Lago de Chapala.

~Tomodactylus rufescens~ Duellman and Dixon

_Tomodactylus rufescens_ Duellman and Dixon, Texas Jour. Sci., 11:78, March, 1959.--Dos Aguas, Michoacan, Mexico.

Dos Aguas (14); 18 km. E of Dos Aguas (6).

Fourteen specimens from the pine-oak forests around Dos Aguas (UMMZ 118503-10, 121498-9) have reddish brown dorsal color and a narrow cream-colored middorsal line (Pl. 5, Fig. 2). Twelve of these specimens are adult males having snout-vent lengths of 20.7 to 24.6 (22.5) mm. One female has a snout-vent length of 24.8 mm., and one juvenile has a snout-vent length of 14.5 mm. Six specimens are from a region of mixture of pine-oak forest and arid tropical scrub forest at 18 kilometers east of Dos Aguas (UMMZ 121497, 121500). All are males having snout-vent lengths of 18.0 to 22.6 (20.7) mm. The dorsum is tan marked with black; the thighs are yellowish orange.

The specimens from 18 kilometers east of Dos Aguas were found on July 22, 1960, by Floyd L. Downs and John Winklemann, who collected calling males of _Tomodactylus rufescens_ and _Tomodactylus nitidus petersi_ at the same locality. Downs (_personal communication_) stated the call was a single note. At Dos Aguas I heard _T. rufescens_ give two calls, one a single "peep," the other a triple note--"pee-ee-eep."

In the higher parts of the Sierra de Coalcoman _Tomodactylus rufescens_ seems to fill the same niche as _T. angustidigitorum_ does in the Cordillera Volcanica. At lower elevations in their respective mountain ranges the species occur sympatrically with _T. nitidus petersi_.

~Diaglena reticulata~ Taylor

_Diaglena reticulata_ Taylor, Univ. Kansas Sci. Bull., 28:60, May 15, 1942.--Cerro Arenal, Oaxaca, Mexico.

Nueva Italia (3); Ostula (7).

Until recently frogs of the genus _Diaglena_ were known only from a few specimens from southern Sinaloa (_Diaglena spatulata_) and from the Pacific lowlands of the Isthmus of Tehuantepec (_Diaglena reticulata_). Peters (1955a) reported specimens from Ostula, Michoacan, and compared these specimens with one _D. reticulata_ from Tehuantepec, Oaxaca, and four _D. spatulata_ from Sinaloa. This comparison showed that the specimens from Michoacan, although showing some minor differences from _D. reticulata_, are closer to that species than to _D. spatulata_. Subsequent to Peters' work, series of both species of _Diaglena_, including additional specimens from Michoacan and from Colima, have been collected, and a more qualified comparison is now possible.

In comparing specimens of _D. spatulata_ from southern Sinaloa (UMMZ 115322) with specimens of _D. reticulata_ from Tehuantepec, Oaxaca (UMMZ 115321), the differences noted by Taylor (1942c:60) were found to be constant. But specimens from Ostula, Michoacan (UMMZ 104418), and five individuals from Colima (TNHC 26379-83) were found to be intermediate in certain characters. The skin of the dorsum in _D. reticulata_ is granular; that in _D. spatulata_ is smooth. The skin in specimens from Ostula and Colima is slightly granular. The dorsal ground color of _D. reticulata_ is yellowish brown with dark reticulations; the dorsal ground color of _D. spatulata_ is olive-green. Specimens from Ostula and Colima most closely resemble those from Tehuantepec in coloration, but the reticulations are more coarse, and the ground color has an olive-green tint. _Diaglena reticulata_ also differs from _D. spatulata_ in having a larger over-all size, slightly broader head, a narrower interorbital distance, and a more pointed snout with a deeper labial shelf (Table 4). The specimens from Ostula and Colima are intermediate between _D. reticulata_ from Oaxaca and _D. spatulata_ from Sinaloa in body proportions.

Of three specimens from the Tepalcatepec Valley (JRD 5991-3), only two are suitable for measuring. These specimens are smaller than adults from the coastal areas and have broader heads and snouts, but narrower interorbital distances, than specimens in the other samples (Table 4). The texture of the skin is like that of specimens from Ostula and Colima. The coloration resembles that of _D. reticulata_, but the reticulations are bold and form indistinct bands on the hind limbs.

TABLE 4.--COMPARISON OF FOUR CHARACTERS IN FIVE SAMPLES OF DIAGLENA. (ALL DATA ARE FOR MALES; MEANS GIVEN IN PARENTHESES BELOW RANGES.)

+-----------------+---------+----------+----------+---------+-----------+ | | | | Head | Inter- |Internarial| | | | | width | orbital | distance | | | Number |Snout-vent| |distance | | | Locality | of | length |----------+---------+-----------+ | |specimens| |Snout-vent| Head | Head | | | | | length | width | width | +-----------------+---------+----------+----------+---------+-----------+ | Oaxaca | 9 |71.1-87.5 |25.4-29.1 |63.0-71.4| 11.9-13.8 | | | | (80.7) | (27.9) | (67.1) | (12.9) | +-----------------+---------+----------+----------+---------+-----------+ | Coast of | 5 |72.0-79.2 |24.3-27.2 |67.0-73.8| 13.7-14.4 | | Michoacan | | (74.8) | (25.6) | (71.4) | (14.1) | +-----------------+---------+----------+----------+---------+-----------+ | Colima | 4 |71.7-79.6 |26.1-28.6 |70.5-75.3| 16.0-17.9 | | | | (74.8) | (27.4) | (72.0) | (16.6) | +-----------------+---------+----------+----------+---------+-----------+ | Tepalcatepec | 2 |63.0-65.4 |28.3-32.2 |57.3-62.4| 17.0-20.2 | | Valley | | (64.2) | (30.3) | (59.9) | (18.6) | +-----------------+---------+----------+----------+---------+-----------+ | Sinaloa | 11 |71.9-81.3 |24.0-27.3 |70.5-78.1| 15.0-17.3 | | | | (77.3) | (25.7) | (73.4) | (16.1) | +-----------------+---------+----------+----------+---------+-----------+

All specimens from Michoacan and Colima more closely approach _Diaglena reticulata_ than _D. spatulata_. The acquisition of additional specimens, especially from the area between Sinaloa and Colima and from Guerrero, is necessary to determine the relationships among the various populations known at present. Both species of _Diaglena_ inhabit tropical scrub forest; none has been found in the more humid and tropical semi-deciduous forests. Humid forest replaces the scrub forest in the lowlands of southern Nayarit and northern Jalisco; possibly this forest acts as a barrier to the distribution of _Diaglena_ and thus serves as a divider between the ranges of _D. spatulata_ to the north and _D. reticulata_ to the south.

~Pternohyla fodiens~ Boulenger

_Pternohyla fodiens_ Boulenger, Ann. Mag. Nat. Hist., ser. 5, 10:326, 1882.--Presidio, Sinaloa, Mexico.

Nueva Italia (2).

These specimens (JRD 5994-5) were found on the road near Nueva Italia during a heavy rain on the night of August 25, 1960, by James R. Dixon. Both are females having snout-vent lengths of 64.0 and 59.0 mm. They are typical of the species as it is known from Sinaloa, Nayarit, Jalisco, and Colima.

These specimens constitute the southernmost record for the species, which ranges in semi-arid habitats from southern Arizona southward along the Pacific lowlands of Mexico to Colima and inland on the Mexican Plateau in Jalisco.

~Phyllomedusa dacnicolor~ Cope

_Phyllomedusa dacnicolor_ Cope, Proc. Acad. Nat. Sci. Philadelphia, 16:181, September 30, 1864.--Colima, Colima, Mexico. Funkhouser, Occ. Pap. Nat. Hist. Mus. Stanford Univ., 5:37, April 1, 1957.

_Agalychnis alcorni_ Taylor, Copeia, no. 2:31, June 2, 1952.--Rio Tepalcatepec, 17 miles south of Apatzingan, Michoacan, Mexico.

_Agalychnis dacnicolor_, Duellman, Herpetologica, 13:29, March 30, 1957.

_Phyllomedusa alcorni_, Funkhouser, Occ. Pap. Nat. Hist. Mus. Stanford Univ., 5:30, April 1, 1957.

Aguililla (13); Apatzingan (7); Charapendo; Coahuayana (3); Coalcoman (54); El Sabino; Huetamo Road (2); La Orilla; La Placita; Nueva Italia (4); 32 km. E of Neuva Italia (2); Rio Cancita, 14 km. E of Apatzingan; Rio Tepalcatepec, 27 km. S of Apatzingan; Salitre de Estopilas (2); Tzitzio (4).

This large tree frog has been found only in the lowlands below elevation of about 1000 meters, usually in arid tropical scrub forest. Calling males were heard on rainy nights throughout the rainy season; in nearly every instance both males and females were found in low trees and bushes. On summer nights when there had been no rain, adults were found sitting on bushes in the scrub forest.

At Coalcoman on July 1, 1955, a chorus was heard at midday. About forty _Phyllomedusa dacnicolor_ were found in one guayava bush at the edge of a recently dried pond. Individual males were calling; clasping males were silent. The call is a barking groan. Fifteen individual egg masses were hanging from branches and leaves in tear-drop fashion. Each egg mass contained 100 to 350 pale green eggs, located only in the exterior part of the clear gelatinous mass. Two composite egg masses appeared to have been made up by egg deposition on the part of three to five females (Pl. 2, Fig. 2).

As shown by Duellman (1957a), the characters used by Taylor (1952) to diagnose _Phyllomedusa alcorni_ are sexually dimorphic. Funkhouser (1957) apparently was unaware of this sexual dimorphism, for she recognized _P. alcorni_ and _P. dacnicolor_ as distinct species.

~Phrynohyas inflata~ (Taylor)

_Acrodytes inflata_ Taylor, Univ. Kansas Sci. Bull., 30:64, June 12, 1944.--La Venta, Guerrero, Mexico.

_Phrynohyas inflata_, Duellman, Misc. Publ. Mus. Zool. Univ. Michigan, 96:19, February 1, 1956.

_Phrynohyas corasterias_ Shannon and Humphrey, Herpetologica, 13:15, March 30, 1957.--4.8 miles east of San Blas, Nayarit, Mexico.

Barranca de Bejuco.

One specimen of this large species was collected in 1951; it was found on a low branch in tropical semi-deciduous forest at an elevation of 65 meters. In life there were olive-gray blotches on a pale gray dorsum; the iris was a dark golden color.

This species, which is known from only a few specimens, seems to be restricted to the coastal lowlands and low foothills from Guerrero northward to Nayarit. Shannon and Humphrey (1957) described _Phrynohyas corasterias_ from Nayarit. Their description was based on a small female having a snout-vent length of 34.4 mm. The new species was diagnosed as differing from _P. inflata_ in having less webbing on the feet, a poorly developed supratympanic fold, a more pustulate dorsum, and marked differences in dorsal pattern, color, and nature of antebrachial banding. The significance of the webbing was questioned by Shannon and Humphrey. The nature of the supratympanic fold and dorsal pustules changes with age (Duellman, 1956a:31). _Phrynohyas inflata_ is known to attain a snout-vent length of 95 mm. Dermal structures that undergo ontogenetic change are of little importance in comparing a juvenile with a large adult. The only significant difference in color pattern between _P. inflata_ and _P. corasterias_ is the presence of wide transverse bands on the limbs of the latter. In this respect _P. corasterias_ approaches _P. latifasciata_, a species known only from two specimens from southern Sinaloa. The acquisition of additional specimens from Jalisco, Nayarit, and Sinaloa may show that _P. inflata_ and _P. latifasciata_ are conspecific, as suggested by Duellman (1956a:21). Nonetheless, the specimen on which the description of _P. corasterias_ was based is not sufficiently different from the known specimens of _P. inflata_ to warrant specific recognition.

~Hyla arenicolor~

_Hyla arenicolor_ Cope, Jour. Acad. Nat. Sci. Philadelphia, ser. 2, 6:84, July, 1866.--Northern Sonora, Mexico. Type locality restricted to Santa Rita Mountains, Pima County, Arizona, by Smith and Taylor (1950a:354).

Agua Cerca; Cascada Tzararacua (3); Chinapa; Cojumatlan; Dos Aguas; El Sabino (25); El Espinal; Lago de Camecuaro; Lombardia (2); Tupataro; Zinapecuaro.

Altitudinally this frog ranges from 500 to 2100 meters; although the environments in which it has been found vary from open arid tropical scrub forest to pine forest, it usually is found near rocky streams in these habitats. There is great disparity in size between specimens from the mountains and those from the Tepalcatepec Valley. Seven males from elevations in excess of 1400 meters have an average snout-vent length of 34.7 mm.; nine from elevations below 1000 meters have an average snout-vent length of 49.1 mm. In life a male collected at night at Lombardia (UMMZ 112846) had dark brown spots on a grayish brown dorsum; the groin, anterior and posterior surfaces of the thighs, and ventral surfaces of the hind limbs and palms were yellowish orange. The belly and tips of digits were white; the vocal sac was purplish brown, and the iris was dark grayish gold. In contrast, a specimen obtained in the daytime at Chinapa (UMMZ 119204) had indistinct gray spots on a pale ashy gray dorsum; the flash colors were yellow. After dark the spots were dark olive-brown on a grayish brown dorsum.

Two males were found calling from a rocky stream near Lombardia on July 12, 1955. The call is a nasal "ah-ah-ah-ah."

~Hyla baudini~ Dumeril and Bibron

_Hyla baudinii_ Dumeril and Bibron, Erpetologie generale, vol. 8:564, 1841.--Mexico. Type locality restricted to Cordoba, Veracruz, Mexico, by Smith and Taylor (1950a:346).

Aguililla (5); Apatzingan (30); Arteaga; Buena Vista; Charapendo; Coahuayana; Cofradia (4); El Sabino (12); La Placita; La Playa; Maruata; Nueva Italia (3); 32 km. E of Nueva Italia (2); Ostula (4); Rio Tepalcatepec, 25 km. S of Apatzingan (3); Salitre de Estopilas; San Jose de la Montana (2); Tumbiscatio; Tzitzio.

This tree frog is widespread in the coastal lowlands and in the Tepalcatepec Valley up to elevations of about 1200 meters. It is found in numbers in the early part of the rainy season, at which time males were heard calling from bushes and trees along ditches and temporary ponds. The call is a loud nasal "waank-waank-waank." One individual that was emitting a long and unusually high-pitched call was found to have one hind limb engulfed by a _Leptodeira maculata_.

When active at night these frogs usually are pale tan to reddish brown above with dark brown markings. A specimen found sitting on a maguey plant in the daytime was pale ashy gray with a pale green upper lip.

~Hyla bistincta~ Cope

_Hyla bistincta_ Cope, Proc. Amer. Philos. Soc., 17:87, 1877.--Veracruz, Mexico. Type locality restricted to Acultzingo, Veracruz, Mexico, by Smith and Taylor (1950a:346).

Cerro San Andres; Dos Aguas (2); Los Conejos (3); Uruapan (50).

In the Parque Nacional at Uruapan this species was found in abundance during the day. The frogs hide in an entanglement of vines and vegetation overhanging several small spring-fed streams. Tadpoles were in the rocky streams, and metamorphosing young were on vegetation at the edges of the streams.

In life the dorsum is greenish tan with brown mottling; in some individuals the entire dorsum is dark chocolate brown. The flanks are pale lemon yellow barred with lavender-brown. Notes on the color of a living frog from Dos Aguas (UMMZ 119193) are: Dorsal ground color a medium shade of brown with dark brown flecks; flanks black with silvery white and pale yellow spots; belly pale yellowish white; throat mottled with grayish brown; iris pale copper color.

Description of Tadpole: Body somewhat depressed; maximum width of body slightly more than one-half of body length. Nostrils placed dorsolaterally and directed anteriorly, situated about midway between tip of snout and eye. Eyes of moderate size, dorsolateral in position and directed upwards. Tail about twice as long as body, thrice as long as deep, and tapering gradually to a rounded tip. Tail-musculature not extending to tip of tail fin. Spiracle sinistral, lateral, and situated at midbody. Vent dextral; the cloacal tube extending along ventral part of tail for a distance equal to about one-eighth of body length (Fig. 8). Average body length of six tadpoles with small hind limb buds, 19.5 mm.; tail length, 38.3 mm. Mouth ventral, its width equal to about two-thirds of greatest width of body. Lips bordered by two rows of small papillae; row of larger papillae between upper lip and outer upper tooth-row, similar row between lower lip and outer lower tooth-row; laterally these rows degenerating into numerous small papillae. Horny beaks well developed; upper beak moderately arched and deeply indented; lower beak slightly indented. Serrations of beaks blunt and peglike, moderately developed on both beaks, but slightly stronger on lower one. Tooth-rows 2/3; upper rows nearly equal in length and slightly longer than lower rows, which are subequal in length; inner upper tooth row interrupted medially by rounded notch; inner lower tooth-row turned downward laterally; teeth in all rows about equal in size, but decreasing in length laterally (Fig. 9).

Color in formalin: pale grayish brown dorsally and laterally; pale gray ventrally; tail-musculature brown; tail-fin translucent with scattered melanophores most numerous on upper fin.

In most details these tadpoles resemble those of _Hyla robertsorum_ described by Rabb and Mosimann (1955).

Four metamorphosing young have snout-vent lengths of 23.0-23.5 (23.2); a completely metamorphosed individual has a snout-vent length of 24.8 mm.

In Michoacan this stream-breeding hylid occurs at elevations of 1,600 to 2,400 meters in the Sierra de Coalcoman and in the mountains rising from the Mexican Plateau.

~Hyla eximia~ Baird

_Hyla eximia_ Baird, Proc. Acad. Nat. Sci. Philadelphia, 7:61, October 20, 1854.--Valley of Mexico. Type locality restricted to Coyoacan, Distrito Federal, Mexico, by Smith and Taylor (1950a:329).

_Hyla microeximia_ Maslin, Herpetologica, 13:81, July 10, 1957.--3 miles northwest of Jocotepec, Jalisco, Mexico.

Ciudad Hidalgo (36); Cuitzeo; 29 km. NW of Jacona; Jiquilpan (2); Lago de Camecuaro (2); Lago de Patzcuaro (129); Los Reyes; Morelia; Sahuayo (3); San Gregorio (63); Tangamandapio (4); Temazcal (26); Tupataro; Tuxpan (15); Undameo (2); Uruapan (20); Zacapu; Zamora (27); Zinapecuaro (10).

More than 80 per cent of the specimens from Michoacan have brown spots between the lateral and dorsolateral dark stripes, and more than 50 per cent have spots between the dorsolateral stripes, at least posteriorly. In comparison with specimens from the Valley of Mexico, those from Michoacan have more distinct dorsolateral stripes that extend farther anteriorly, sometimes to the eyelid, and in this respect are more nearly like those from Jalisco and Nayarit (Taylor, 1939b:425). Some specimens from the western part of Michoacan possess certain characters used by Maslin (1957:81) to distinguish _Hyla microeximia_ from _H. eximia_; nevertheless, the variation is such that two species cannot be distinguished in Michoacan. Four series of freshly preserved specimens have been studied in detail; in the discussion below they are arranged from west to east; the measurement is for snout-vent length of ten males from each sample:

_Zamora._--Twenty-two specimens (UMMZ 102083), 24.0-27.6 (26.1) mm. Dorsolateral dark stripe, or row of dashes, present in all specimens; dark spots in lateral and dorsal green fields; lateral dark stripe confluent with dorsolateral stripe posteriorly in 18 specimens; white line not extending to groin.

_Temazcal._--Thirty-five specimens (UMMZ 119162), 26.5-31.1 (28.2) mm. Dorsolateral dark stripe of row of spots present only posteriorly in most; both dorsolateral stripes and dorsal spots lacking in four specimens; heavy spotting dorsally in three others; lateral and dorsolateral dark stripes confluent posteriorly in three; lateral white stripe extending to groin in 16 specimens.

_Ciudad Hidalgo._--Thirty-six specimens (UMMZ 119163), 26.4-30.9 (28.2) mm. Dorsolateral dark stripe or row of spots present only posteriorly in most; no brown spots in the green fields of many specimens; large brown inguinal spot in most specimens; heavy spotting dorsally in four; lateral and dorsolateral dark stripes confluent posteriorly in five; lateral white line extending to groin in most specimens.

_Tuxpan._--Fifteen specimens (UMMZ 115227), 28.7-33.0 (30.5)