University of Kansas Publications

Museum of Natural History

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

December 20, 1961

The Amphibians and Reptiles of Michoacán, México

BY

WILLIAM E. DUELLMAN

University of Kansas
Lawrence
1961

University of Kansas Publications, Museum of Natural History

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

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

University of Kansas
Lawrence, Kansas

PRINTED IN
THE STATE PRINTING PLANT
TOPEKA, KANSAS
1961

[Pg 3]

The Amphibians and Reptiles of Michoacán, México

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 México. 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 Michoacán. 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 Michoacán. Such was the beginning of my interest[Pg 4] in the
herpetofauna of the region. I have been fortunate to return to Michoacán
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
Coalcomán. But it soon became evident that in order to understand the
relationships of the herpetofauna of the Sierra de Coalcomán, 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 Michoacán already in museums.

There have been few detailed herpetofaunal studies in México. 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 Gómez Farías 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 Marías 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 Michoacán. The purpose of this part is to present a full
account of the species of amphibians and reptiles known to inhabit the
state of Michoacán; 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[Pg 5] 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 Michoacán 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 Michoacán 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 Michoacán; 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 Michoacán 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
Michoacán. Norman E. Hartweg allowed me to use the specimens and data
that he gathered in his survey of the herpetofauna in the region of
Volcán Parícutin. L. C. Stuart, Charles[Pg 6] 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 Michoacán 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 Michoacán. Ingeniero Pedro Tonda aided us in Arteaga
and San Salvador. Ingeniero Anastacio Peréz Alfaro of the Comisión
Tepalcatepec in Uruapan provided the latest maps of southern Michoacán
and much essential information pertaining to travel conditions in the
area. Señor 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 Zirimícuaro. The naval officers at the Estación
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 Comisión 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 Michoacán 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, Jesús, 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[Pg 7] to me the facilities of
the museum and for their numerous courtesies that aided me so much.

My field work in Michoacán 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 México were provided by the
Dirección General de Caza through the courtesy of Ing. Juan Lozano
Franco and Luis Macías Arellano.

Historical Account

Unlike many parts of southern México and northern Central America,
Michoacán received no attention from the collecting expeditions of the
European museums in the last century. The earliest known herpetological
specimens from Michoacán were obtained by Louis John Xantus, who was
appointed U. S. Consul to Colima in 1859. In April, 1863, Xantus
collected at Volcán Jorullo in Michoacán; in April and May of the same
year he collected along the coast of Michoacán between the Río Cachán
and the Río Nexpa. His small collection of 19 extant specimens is in the
United States National Museum. Alfredo Dugès, a resident of Guanajuato,
México, made early contributions to the knowledge of the herpetofauna of
Michoacán. 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 México, Edward W. Nelson and Edward A.
Goldman spent a limited amount of time in Michoacán 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 México, Seth
E. Meek obtained some amphibians and reptiles from Lago de Pátzcuaro 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 Volcán Jorullo and other
localities in the valley. Later in the same year he collected at
Guayabo, San Salvador, and Arteaga in the Sierra de Coalcomán and at
Buena Vista and Cofradía[Pg 8] 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 Michoacán. In the 1930’s Edward H. Taylor and Hobart M. Smith
collected throughout much of México. At various times they worked in
Michoacán, principally along the road from México 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 Pátzcuaro and between Uruapan and Apatzingán; 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 Tancítaro and at Apatzingán; an account of
the specimens collected there was published by Schmidt and Shannon
(1947).

The eruption of Volcán Parícutin 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
Volcánica 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 Coalcomán and adjacent Pacific coast of Michoacán; in the same
year Peters collected also on the Mexican Plateau and at Volcán Jorullo.
His specimens are in the Museum of Zoology at the University of
Michigan. Since 1950 many biologists have collected in Michoacán 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 Michoacán began in 1951, when
I accompanied Donald D. Brand on an exploring[Pg 9] 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
Volcán Jorullo. In July and August we made our headquarters at
Coalcomán. From that town the field party travelled southward to Maruata
on the Pacific coast and thence back over the mountains to Coalcomán.
Later in that summer we travelled by mule from Coalcomán southeastward
to the mouth of the Río Nexpa. In 1955, accompanied by Lee D. Beatty,
Carter R. Gilbert, and Fred G. Thompson, I collected in the Tepalcatepec
Valley and at Coalcomán. We made a mule trip from Coalcomán to Cerro de
Barolosa, where we made the first collections from the pine-fir forests
in the Sierra de Coalcomán. 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 Volcánica 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 Michoacán and again
collected on the Mexican Plateau and in the Cordillera Volcánica, 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 Michoacán 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 Volcánica, and in the Tepalcatepec Valley. Most
of our time was spent in the Sierra de Coalcomán, where we collected at
Aguililla, Artega, and Dos Aguas. In 1960 two days were spent in
Michoacán; a small collection was made in the eastern part of the
Cordillera Volcánica. 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 Michoacán 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[Pg 10] 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 Michoacán,
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 Michoacán.

Physiography

The state of Michoacán comprises an area of 60,093 square kilometers
(Vivó, 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 México; 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 Michoacán can be divided into lowlands and
highlands as follows:

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 Michoacán extends for a distance of
about 200 kilometers (airline) from the Río Coahuayana to the Río
Balsas. The coastal plain is broad between the Río Coahuayana and San
Juan de Lima, and between Las Peñas and the Río Balsas, where the hills
rise some 12 kilometers inland from the sea. Between San Juan de Lima
and Las Peñas 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 Coalcomán and the Sierra del Sur,
but south of the Cordillera Volcánica, is a broad structural depression,
the Balsas-Tepalcatepec Basin. The western part of this basin, which
separates the Sierra de Coalcomán from the Cordillera Volcánica, is the
valley of the Río Tepalcatepec, a major tributary of the Río Balsas. The
eastern part of the basin is the valley of the Río Balsas. From the
point of junction of the two rivers, the Río Balsas flows southward
through a narrow gorge,[Pg 11] which separates the Sierra de Coalcomán from
the Sierra del Sur, to the Pacific Ocean. In Michoacán the floor of the
Balsas-Tepalcatepec Basin varies from 200 to 700 meters above sea level.

The central part of México is a vast table-land, the Mexican Plateau,
the southern part of which extends into northern Michoacán. 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 Michoacán are several lakes, the largest of
which are Lago de Chapala, Lago de Cuitzeo, and Lago de Pátzcuaro.

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

Lying between the Tepalcatepec Valley and the Pacific Ocean, and east of
the Río Coahuayana and west of the Río Balsas, is an isolated highland
mass, the Sierra de Coalcomán. 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 Volcánica, the Sierra de Coalcomán is
isolated from other mountain ranges in southwestern México.

Climate

The climates in Michoacán vary from tropical in the lowlands to cool
temperate at high elevations in the Sierra de Coalcomán and Cordillera
Volcánica. The highest temperatures are known in the Balsas-Tepalcatepec
Basin, where at Churumuco the mean annual temperature is 29.3° C. and
the range of monthly means is 3.5° 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.
(Guzmán-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[Pg 12] 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 Coalcomán probably receive more rain than any
other part of the state. The Balsas-Tepalcatepec Basin lies in a rain
shadow of the Sierra de Coalcomán, and the Mexican Plateau lies in a
somewhat less drastic rain shadow of the Cordillera Volcánica; 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 Michoacán. These
types are as follows:

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 Michoacán the rainfall is heaviest on the southern slopes of the
Sierra de Coalcomán and somewhat less so on the southwestern slopes of
the Cordillera Volcánica. 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[Pg 13] 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
Michoacán will deal with the geographical and ecological patterns of
distribution of the herpetofauna, a brief summary of the faunal
assemblages is presented here.

In Michoacán 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 Volcánica, 45 species of
amphibians and reptiles are known; 34 species have been found in the
Sierra de Coalcomán. Fourteen species are known to occur in both ranges.
Several species are known only from the Cordillera Volcánica and
adjacent highlands, and three species are endemic to the Sierra de
Coalcomán.

ANNOTATED LIST OF SPECIES

In the following pages the 176 species and subspecies of amphibians and
reptiles known to occur in the state of Michoacán 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.[Pg 14]

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 Michoacán 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:

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

Taylor and Smith (1945:530) presented data on 137 specimens collected at
Tacícuaro 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 Pátzcuaro are
tentatively[Pg 15] 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 (Dugès)

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 Pátzcuaro;
nevertheless, none was found on my visits there. In 1956 Charles M.
Bogert obtained several large specimens at the market in Pátzcuaro.
These establish the continued existence of the salamander in Lago de
Pátzcuaro. 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 Pátzcuaro, the specimen probably was from that lake.
Nevertheless, the species may occur in other permanent bodies of water
in Michoacán. Maldonado-Koerdell (1948) described Bathysiredon dumerili
queretarensis from San Juan del Río, Queretaro. This locality is about
200 airline kilometers northeast of Lago de Pátzcuaro and is in the Río
Moctezuma drainage.

Ambystoma ordinarium Taylor

[Pg 16]

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 José 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 José 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.[Pg 17]

Ambystoma tigrinum velasci Dugès

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 Tacícuaro is 61.0 mm.

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

Pseudoeurycea belli (Gray)

This salamander seems to reach its greatest abundance in Michoacán in
the Sierra de los Tarascos between Pátzcuaro and Tancítaro, where it is
found at elevations from 1500 to 2900 meters. It is found less commonly
in the eastern part of the Cordillera Volcánica in Michoacán, 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[Pg 18] 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.

Fig. 1. Diagram of an egg of Pseudoeurycea belli from
San Juan de Parangaricutiro, Michoacán. × 10.

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[Pg 19] 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).

Fig. 2. Correlation between the number of vomerine teeth
and snout-vent length in 79 Pseudoeurycea belli from Michoacán.

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 Michoacán, including one juvenile, lack occipital spots. In the 34
living individuals that I have seen from Michoacán 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)

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,[Pg 20] a series was
collected in pine-fir forest at Puerto Lengua de Vaca. These localities
are between 2900 and 3000 meters in the Cordillera Volcánica in eastern
Michoacán.

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 Michoacán 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 Michoacán have paler venters than do topotypic
specimens.

Salientia

Rhinophrynus dorsalis Duméril and Bibron

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
Río Balsas, the distinctive voice of Rhinophrynus was not heard.
Elsewhere on the Pacific coast of México 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[Pg 21] 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 México
at least as far north as Michoacán.

Scaphiopus hammondi multiplicatus Cope

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

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 México and Central America. Those from
Michoacán 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[Pg 22] 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 México 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 Michoacán. 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

The southwestern terminus of the range of this species is on the Mexican
Plateau in Michoacán. 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.[Pg 23]

Bufo marinus (Linnaeus)

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 México 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 México 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

In Michoacán this species is confined to elevations of less than 1000
meters on the coast and foothills of the Sierra de Coalcomán.[Pg 24] 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.

[Pg 25]

Fig. 3. Adult male of Bufo perplexus from Apatzingán,
Michoacán. × 1.5.

[Pg 26]

Fig. 4. Adult male of Bufo marmoreus from Pómaro,
Michoacán. × 1.5.

PLATE 1

Hatchling of Pseudoeurycea belli from San Juan de Parangaricutiro,
Michoacán. × 8.

PLATE 2

Fig. 1. Nest and eggs of Pseudoeurycea belli beneath a
rock at San Juan de Parangaricutiro. Approx. natural size.

Fig. 2. Multiple egg clutches of Phyllomedusa
dacnicolor from Coalcomán, Michoacán. 1/3 ×.

PLATE 3

Fig. 1. Adult male of Tomodactylus angustidigitorum
from Paracho, Michoacán. × 4.

Fig. 2. Adult male of Tomodactylus fuscus from Los
Cantiles, Michoacán. ×4.

PLATE 4

Fig. 1. Adult male of Tomodactylus nitidus nitidus from
Tuxpan, Michoacán. ×.

Fig. 2. Adult male of Tomodactylus nitidus orarius from
Tecolapa, Colima. × 4.

PLATE 5

Fig. 1. Adult male of Tomodactylus nitidus petersi from
Apatzingán, Michoacán. × 4.

Fig. 2. Adult male of Tomodactylus rufescens from Dos
Aguas, Michoacán. × 4.

PLATE 6

Fig. 1. Adult male of Hypopachus caprimimus from
Tuxpan, Michoacán. × 2-1/2.

Fig. 2. Adult male of Hypopachus oxyrrhinus ovis from
Tangamandapio, Michoacán. × 3.

[Pg 27]

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.)

Taylor (1943a:347) described Bufo perplexus from Mexcala on the Río
Balsas in Guerrero. Among the many paratypes are specimens from Tonolá,
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[Pg 28] coastal populations through the relatively low pass at
Chilpancingo, at the mouth of the Río Balsas, and near the convergent
headwaters of the Río Coahuayana and Río 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 occidentalis Camerano

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 Coalcomán 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[Pg 29] 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.

Fig. 5. Tadpole of Bufo occidentalis (UMMZ 94269) from
Barranca Seca, Michoacán. × 3.

Fig. 6. Mouthparts of larval Bufo occidentalis (UMMZ
94269) from Barranca Seca, Michoacán. × 20.

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).[Pg 30]

Leptodactylus labialis (Cope)

In the Tepalcatepec Valley this frog reaches the northernmost known
limit of its range in western México. 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)

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 Apatzingán 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.[Pg 31]

Leptodactylus occidentalis Taylor

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 México 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 México and individuals of the population
of Leptodactylus in northwestern México (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 México, specimens of melanonotus
from throughout México and northern Central America have yellow or
yellowish brown glands. Specimens from northwestern México have black or
brownish black glands that are conspicuously darker than those found in
melanonotus. Examination of 653 preserved specimens of Leptodactylus
melanonotus from México and Guatemala has failed to reveal specimens
with black ventral glands, like those found in specimens from
northwestern México, to which the name Leptodactylus occidentalis has
been applied. Furthermore, in melanonotus the glands are less distinct
and more extensive than in occidentalis;[Pg 32] 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.

Fig. 7. Diagrammatic view of ventral surfaces of
Leptodactylus melanonotus (A) and Leptodactylus occidentalis (B),
showing usual position and size of glandular areas. Approx. natural
size.

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[Pg 33] México show certain characters that
distinguish them from Leptodactylus melanonotus, as it is known
throughout the rest of México. 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
Concepción (UMMZ 113081), La Resolana (UMMZ 102104), and Tenachitlán
(UMMZ 113045-6). Records for Leptodactylus occidentalis are: Álamos,
Sonora (AMNH 51356-65); Culiacán (AMNH 49511-9), Chele (UMMZ 110914),
and Rosario (UMMZ 113062) in Sinaloa; Ixtlán del Río (UMMZ 102108), San
Blas (UMMZ 112814, 112994, 110892, 115543), and Tepic (UMMZ 115544) in
Nayarit; Ameca (UMMZ 102106-7) and La Cofradía on the south shore of
Lago de Chapala (UMMZ 102105) in Jalisco; and Tangamandapio, Michoacán
(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)

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 José 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[Pg 34] in the eastern part of Michoacán, 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 México.

The largest specimen from Michoacán 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 Volcánica and the southwestern escarpment of
these mountains at elevations from 1450 to 2750 meters.

Microbatrachylus pygmaeus (Taylor)

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.[Pg 35]

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)

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[Pg 36]
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 México shows a similar composition of
color variants. Of 78 specimens from the Río 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 Günther). 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[Pg 37] 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 Michoacán 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

The few specimens indicate that this species occurs at moderate to high
elevations in the state. The specimens from Cherán and Uruapan were
obtained in pine forests; the specimen from Coalcomán 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 Coalcomán (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

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 Michoacán[Pg 38] this frog
has been collected in pine-oak forest at Cascada Tzararacua and at Los
Reyes, in arid scrub forest at Arteaga and Coalcomán, and in tropical
semi-deciduous forest on the lower Pacific slopes of the Sierra de
Coalcomán. 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 Pómaro, 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 México, where Eleutherodactylus
occidentalis extends to the Pacific lowlands.

Eleutherodactylus rugulosus vocalis Taylor

The distributional data on this frog in Michoacán indicate that it
inhabits riparian situations in arroyos and canyons in the lower slopes
of the Cordillera Volcánica and the Sierra de Coalcomán, 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[Pg 39] was grayish
brown. In contrast, individuals from Agua del Obispo, Guerrero, had pale
golden eyes; specimens from Matías Romero, Oaxaca, had gold eyes heavily
flecked with gray; and individuals from Volcán San Martin, Veracruz, had
bronze eyes.

The use of the trinomial here is arbitrary. Frogs of the
Eleutherodactylus rugulosus group in México (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
Michoacán.

Tomodactylus angustidigitorum Taylor

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 Volcán
Parícutin; 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

The range of this species includes the Sierra Ajusco in México and
Morelos and thence westward to the Serranía Ucareo in Michoacán. 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[Pg 40] 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)

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

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 Michoacán this subspecies
has been found only in the coastal region and the lower foothills of the
Sierra de Coalcomán, an area in which[Pg 41] it replaces Tomodactylus nitidus
petersi. This is the only Tomodactylus known to inhabit coastal
lowlands.

Tomodactylus nitidus petersi Duellman

In life, specimens from Apatzingán (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 Apatzingán 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 Volcánica; Zamora and Jiquilpan are on a low part of the
Mexican Plateau southeast of Lago de Chapala.

Tomodactylus rufescens Duellman and Dixon

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.[Pg 42]

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 Coalcomán Tomodactylus rufescens
seems to fill the same niche as T. angustidigitorum does in the
Cordillera Volcánica. At lower elevations in their respective mountain
ranges the species occur sympatrically with T. nitidus petersi.

Diaglena reticulata Taylor

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, Michoacán, and compared
these specimens with one D. reticulata from Tehuantepec, Oaxaca, and
four D. spatulata from Sinaloa. This comparison showed that the
specimens from Michoacán, 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 Michoacán 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, Michoacán (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[Pg 43] 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.)

All specimens from Michoacán 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[Pg 44] 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

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 México to Colima and inland on the Mexican
Plateau in Jalisco.

Phyllomedusa dacnicolor Cope

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 Coalcomán 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[Pg 45] 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)

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[Pg 46] based is not sufficiently different from the known specimens of P.
inflata to warrant specific recognition.

Hyla arenicolor

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 Duméril and Bibron

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[Pg 47] 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

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.

Fig. 8. Tadpole of Hyla bistincta (UMMZ 115231) from
Uruapan, Michoacán. × 2.

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;[Pg 48] 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).

Fig. 9. Mouthparts of larval Hyla bistincta (UMMZ
115231) from Uruapan, Michoacán. × 15.

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[Pg 49] (23.2);
a completely metamorphosed individual has a snout-vent length of 24.8
mm.

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

Hyla eximia Baird

More than 80 per cent of the specimens from Michoacán 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 México, those from
Michoacán 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 Michoacán 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 Michoacán. 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:

As can be seen from the above descriptions, the distinguishing
characters of Hyla microeximia—confluence of lateral and dorsolateral
dark stripes posteriorly, extent of lateral white stripe, and
distribution of dark spots dorsally—are found in individuals from all
of the populations sampled. In the samples from western Michoacán there
is a higher incidence of microeximia-like frogs than in those from
other parts of the state. Hyla eximia is a wide-ranging species
varying greatly geographically and individually. A thorough review of
the species and related members of the Hyla eximia-group is necessary
before certain populations can justifiably be segregated as subspecies
or species.

In Michoacán Hyla eximia has been collected in mesquite-grassland,
pine-oak forest, and cultivated areas on the Mexican Plateau from 1500
to 2300 meters; apparently it is absent from the Sierra de Coalcomán.
This is the most abundant frog on the southern part of the Mexican
Plateau; in the rainy season breeding choruses are found in temporary
pools and in the marshes adjacent to the permanent lakes.

Hyla lafrentzi Mertens and Wolterstorff

In March, 1949, James A. Peters collected this species at elevations of
2400 to 2800 meters on the west slope of Cerro San Andrés. The frogs
were found beneath logs and rocks in a damp canyon in coniferous forest.
Among the juveniles in this series is a completely transformed
individual (UMMZ 102093) having a snout-vent length of 14.5 mm. Five
adults have snout-vent lengths of 36.2-39.5 (38.0) mm. Hyla lafrentzi
has noticeably longer hind limbs than H. eximia; in the former, when
the hind limb is brought forward along the body, the tibiotarsal
articulation extends to the snout. There are dark transverse bands on
the hind limbs; the dorsolateral stripe is broken into an anterior and a
posterior segment, and the latter is narrowly bordered by white in most
specimens.[Pg 51]

Hyla lafrentzi occurs at higher elevations than any other frog in
Michoacán; the locality records from throughout the range indicate that
it is restricted to pine and pine-fir forests. In these habitats it
replaces Hyla eximia, which inhabits the lower pine-oak forests and
mesquite-grassland on the Mexican Plateau. Ponds are absent at places
where Hyla lafrentzi has been collected; possibly the eggs are laid in
streams.

Hyla smaragdina Taylor

Taylor (1940a:18) diagnosed this species as having few or no vomerine
teeth, no vocal sac, a rather broad and flat head, two large tubercles
below the anus, a granular venter, and a green dorsum in life. The
specimens on which the description was based are either immature or
non-breeding individuals; all were collected from bromeliads growing on
cacti near Cojumatlán. Another small, flat-headed hylid from Tepoztlán,
Morelos, was described and diagnosed by Taylor (1943b:49) as differing
from Hyla smaragdina in having a vocal sac and a broader head. This
specimen was named Hylella azteca. Specimens from the coastal region
of Michoacán and Colima were referred to Hylella azteca by Peters
(1954:7) and Duellman (1958c:8).

Comparison of topotypic Hyla smaragdina and the holotype of Hylella
azteca (UIMNH 25044) with the several series of specimens from
Michoacán has resulted in the conclusion that all pertain to only one
species. Although the type series of Hyla smaragdina consists of
immature specimens, the males in that series do possess vocal sacs.
Since these were not breeding individuals, the sacs are not well
developed. The characters of the anal tubercles and the relative width
of the head are of no value in separating the two species. The
apparently aestivating individuals comprising the type series of Hyla
smaragdina, and the type of Hylella azteca, which also was found in a
bromeliad, were green in life. Of the calling males found on the coast
of Michoacán, most were yellowish tan when found; two were pale green,
but soon changed to pale tan. Calling males from Copuyo and Dos Aguas
were pale yellowish tan. Therefore the color of the dorsum is of little
significance in distinguishing the two named populations.[Pg 52]

Males of Hyla smaragdina have been found calling in the months of June
and July from rocky streams; the call is a nasal “haah-haah-haah,”
repeated quickly and constantly for as long as 30 seconds. As pointed
out by Duellman (1958c:9), this breeding behavior is unlike that
suggested by Taylor (1943b:51). In Michoacán Hyla smaragdina has been
found in tropical semi-deciduous forest, oak forest, and
mesquite-grassland at elevations from 150 to 1500 meters.

Hyla smithi Boulenger

This small hylid is abundant in the Tepalcatepec Valley to elevations of
about 1000 meters; it was found infrequently on the coastal lowlands.
Males call from bushes in and around flooded fields and ditches, from
grasses and small herbs in the water and from vegetation overhanging
small streams. The call consists of a series of short, high notes,
somewhat reminiscent of a katydid’s song. In the dry season occasional
males were heard calling from irrigated fields near Apatzingán. In the
daytime individuals were found in the axils of leaves of the
elephant-ear plants (Xanthosoma).

In living individuals the dorsal color usually is uniform pale yellow;
often the lateral white stripe is barely visible. The vocal sac is
bright yellow, and the iris is pale gold. In some individuals there are
scattered dark brown spots or flecks on the back and upper surfaces of
limbs. Twenty males from Apatzingán have the following measurements:
snout-vent length, 22.8-26.0 (25.0) mm., tibia length, 10.7-13.6 (12.6)
mm.; head width, 7.2-8.0 (7.6) mm., head length, 7.1-8.1 (7.7) mm.

Hypopachus caprimimus Taylor

Specimens of Hypopachus from the Balsas drainage in Michoacán have
characters consistent with topotypic H. caprimimus. Eleven specimens
from the southern edge of the Mexican Plateau all have the flanks darker
than the dorsum, a distinct and continuous dark stripe from the occiput
to the groin, a large dark spot in the inguinal region, and a pair of
dark transverse stripes on the thigh and shank[Pg 53] (Pl. 6, Fig. 1). With
the exception of three specimens from Charapendo, all have a
predominantly brown venter with round, cream-colored spots.

Peters (1954:8) referred specimens from Buena Vista and San Salvador to
Hypopachus oxyrrhinus. He stated that the specimen (BMNH
1914.1.28.150) from San Salvador had flanks much darker than the dorsum
and a well-defined continuous stripe from the occiput to the groin; this
specimen has the characters of H. caprimimus. The specimen (BMNH
1914.1.28.151) from Buena Vista resembles H. oxyrrhinus in some
characters, but it is not like H. oxyrrhinus ovis on the Mexican
Plateau in Michoacán. The specimen has paired transverse stripes on the
hind limbs as does H. caprimimus, and is here referred to that
species.

In Michoacán this species has been collected in arid tropical scrub
forest at elevations of 200 to 1800 meters in the northern foothills of
the Sierra de Coalcomán, the Tepalcatepec and Tuxpan valleys, and on the
lower slopes of the Cordillera Volcánica. Calling males have been found
along streams. One specimen from Charapendo was regurgitated by a
Leptodeira maculata.

Hypopachus oxyrrhinus ovis Taylor

Thirty-seven specimens from the Mexican Plateau in northwestern
Michoacán agree well with the diagnosis of Hypopachus oxyrrhinus ovis
by Shannon and Humphrey (1958). With the exception of one specimen from
Tangamandapio, all have dark bellies extensively mottled or spotted with
cream-color. Most of the specimens have some form of an irregular,
usually broken, dark line from the occiput to the groin. In eight
specimens there is no line or linear arrangement of spots; instead the
dorsum is spotted or flecked with dark brown. The ground color of the
dorsum and flanks varies from dull reddish brown to grayish brown;
cream-colored spots are evident on the flanks and posterior surfaces of
the thighs in all specimens (Pl. 6, Fig. 2).

In comparison with 14 specimens from Quesería, Colima (UMMZ 80001-2),
individuals from the Mexican Plateau have a[Pg 54] darker venter with bolder
markings, and a more mottled dorsum.

In Michoacán this species has been taken between 1500 and 2200 meters on
the Mexican Plateau, where it inhabits mesquite-grassland and cultivated
areas.

Rana dunni Zweifel

Aside from the type series of this species, there are in the Museum of
Zoology at the University of Michigan six specimens taken from “tanks”
at the limnological station at Pátzcuaro by Paul S. Martin in 1948, and
eight specimens found in shaded ditches along the Río de Morelia by
Robert R. Miller on April 4, 1957. The Río de Morelia flows into Lago de
Cuitzeo; this drainage is separated from Lago de Pátzcuaro by a chain of
hills about 2400 meters in elevation. Dr. Richard G. Zweifel has
examined these specimens and has informed me that, although they differ
slightly from typical Rana dunni, they are much closer to that species
than to Rana montezumae.

Rana megapoda Taylor

These specimens (USNM 113998-114005) are from the marshes along the
southeastern shore of Lago de Chapala. Five females have snout-vent
lengths of 124.0-138.1 (131.5), and one male has a snout-vent length of
110.2 mm. Two juveniles have snout-vent lengths of 49.7 and 56.3 mm. The
coloration of the juveniles is more bold than that of the adults. The
body proportions of these specimens agree with those presented by
Zweifel (1957:80).

Rana montezumae Baird

This species probably is more abundant and widespread than is indicated
by the few specimens listed above. It has been found only in the
vicinity of permanent water on the Mexican Plateau and the mountains
rising from the plateau at elevations of 1500[Pg 55] to 2000 meters. Its
apparent absence from Lago de Pátzcuaro cannot be explained, unless
Rana dunni replaces it there.

Rana pipiens Schreber

Except on the Pacific lowlands, this species is abundant throughout the
state. It has been collected from sea level to 2800 meters, the greatest
altitudinal range of any amphibian in Michoacán. It has been found
frequently in the Tepalcatepec Valley; it is not a distinctly highland
species in southern Michoacán, as stated by Peters (1954:9). One
specimen from Aguililla (UMMZ 119257) is an albino. In this specimen
there is a faint pattern on the hind limbs; otherwise the entire body is
creamy white; the eyes are pink.

Rana pustulosa Boulenger

Although Rana pustulosa seems to be absent from the Mexican Plateau in
Michoacán, it has been collected at elevations of 850 to 2150 meters on
the slopes of the Cordillera Volcánico and in the Sierra de Coalcomán.
Usually the frogs are found along rocky streams, but at Coalcomán they
were found in a hyacinth-choked old river channel, and at El Sabino, in
irrigation ditches.

In most specimens the dorsum is dark olive-brown; in some it is pale
olive-tan with dense dark brown mottling on the back and dark transverse
bands on the hind limbs.

Thirteen tadpoles (UMMZ 94271) taken from a seepage pool by a stream
near Uruapan closely resemble the description of tadpoles of this
species given by Taylor (1942b).

[Pg 56]

REPTILIA

Testudines

Chelonia mydas (Linnaeus)

Green sea turtles are abundant along the coast of Michoacán. Laying
females and fresh nests were found on August 6-12, 1950, July 14-16,
1951, and July 8-10, 1955. The general account of sea turtles on the
coast of Michoacán that was given by Peters (1957) is supplemented here
by my field notes on the actions of one female observed on the night of
July 14, 1951, near Maruata by Donald D. Brand and I. Because of a full
moon, visibility was excellent.

In the course of the day several Chelonia were seen in the surf;
shortly after dark the first turtle was observed on the beach. Several
were observed to come out on the beach and crawl nearly to the strand
line, only to return to the sea.

At 10:20 p. m. one turtle was seen about 15 meters from the water. We
watched this turtle from some distance and observed that by 10:26 p. m.
she had moved about ten meters to a bank of sand about two meters high.
Ten minutes later she had climbed the bank and disappeared over the top
into the brush. We moved closer and remained hidden below the bank.
Although we could not see the turtle, we could hear her movements.
Between 10:37 and 10:57 p. m. the turtle dug, often flipping the dry
sand for a distance of about two meters. When this energetic digging
ceased, we moved up the bank to see that she was facing inland and
sitting in a depression about one and one-half meters in diameter and 30
centimeters in depth. She had cleaned out this depression in the past 20
minutes. Between 11:00 and 11:36 p. m. she dug the nest hole by first
scooping sand with one hind flipper and then with the other; when sand
was thrown by one flipper, there was a similar, but weaker, motion by
the other flipper. At 11:36 p. m. she stopped digging. By crawling up
behind the turtle we were able to examine the nest cavity, which
measured 21 centimeters across the top and 38 centimeters deep. The
diameter of the bottom of the hole was estimated to be about 50
centimeters. At 11:40 p. m. she released the first egg; a minute later
she dropped the second. At 11:42 p. m. the third and fourth eggs were
released; these were coherent, as were the fifth and sixth eggs released
at 11:43 p. m. After this, as many as three eggs[Pg 57] were dropped at a
time. After laying about 60 eggs, she paused for a minute and then
continued laying. By 11:55 p. m. she had laid 98 eggs; after this, the
process of deposition slowed considerably. She dropped a fragment of an
egg followed by normal eggs. At midnight she deposited a miniature egg
about 20 mm. in diameter. This terminated the deposition. Immediately
she began to cover the nest.

Within ten minutes after the last egg was deposited the nest had been
covered. The turtle first had been seen at 10:20 p. m.; judging from its
speed and its distance from the water, the turtle probably had been on
land for about ten minutes. About 25 minutes were used in crawling from
the water to the nesting site. One hour and 33 minutes were spent at the
nesting site; of this time twenty minutes were taken for egg deposition.
The turtle was not followed back to the water, but if the return trip
took approximately the same amount of time as required to travel from
the ocean to the nesting site, the total elapsed time from departure to
return to the water was about two and one-half hours.

We collected the eggs as they were deposited. There were 106 eggs, each
having a diameter of about 40 mm., plus one small egg and a fragment of
another. The turtle had a carapace about one meter in length.

From our limited observations of sea turtles and their tracks on the
beaches, and from the accounts of these animals by the residents of the
coastal region, great numbers of sea turtles use these relatively
uninhabited beaches for nesting grounds. However, the turtles do not go
unmolested. The natives capture turtles and collect their eggs. Opened
and emptied nests also showed signs of predatory activity on the part of
other mammals. In the vicinity of Playa Azul several turtles were killed
by dogs.

Kinosternon hirtipes hirtipes Wagler

One specimen from eight kilometers west of Ciudad Hidalgo (UIMNH 24707)
is from the Río Tuxpan, a tributary of the Río Balsas; this is the only
record for the species from the Balsas drainage. All others are from the
lakes or rivers flowing into the lakes on the southern part of the
Mexican Plateau. This species exists[Pg 58] in Lago de Pátzcuaro to the
apparent exclusion of the abundant and widespread Kinosternon
integrum.

Kinosternon integrum LeConte

Excepting Lago de Pátzcuaro, Kinosternon integrum occupies all
permanent and temporary ponds, lakes, and streams below 2200 meters
throughout the state. At Coalcomán the species was in roadside ditches,
small puddles, flooded fields, a hyacinth-choked ox-bow of the Río
Coalcomán, as well as in the Río Coalcomán and its tributaries.
Specimens from Arteaga and Barranca de Herradero were found in clear
rocky streams; the one from Las Higuertas was found in a small muddy
pond in pine-oak forest.

On August 26, 1960, James R. Dixon found a copulating pair in a pool at
Capirio. The large series from Coalcomán contains juveniles and adults;
these turtles formed the basis for the study of relative growth of
plastral scutes in this species by Mosimann (1956).

Geoemyda rubida perixantha Mosimann and Rabb

These specimens have been discussed in detail by Mosimann and Rabb
(1953). All are from the arid tropical scrub forest; those from the
coastal regions were collected at elevations of less than 40 meters, and
those from the Tepalcatepec Valley were collected at an elevation of 335
meters.

Crocodilia

Crocodylus acutus acutus Cuvier

The crocodile or “caiman” is abundant in the brackish lagoons along the
cost of Michoacán; three large adults and several juveniles[Pg 59] were
observed at Estero Pichi at Playa Azul; others were seen at Mexiquillo
and Maruata. Residents of the Balsas-Tepalcatepec Basin frequently have
reported “caimanes” in the Río Balsas and Río Tepalcatepec, but the
existence of the crocodile in these rivers has not been verified by
specimens.

Sauria

Phyllodactylus duellmani Dixon

This species is known only from the Tepalcatepec Valley, where it has
been found in open arid situations from 180 to 500 meters. Specimens
were found in the daytime in stumps, dead cacti, and the hollow branches
of the legume, Apoplanesia paniculata. In life adults were pale gray
or grayish tan above and creamy white below. A juvenile having a
snout-vent length of 18 mm. had a pale orange tail with gray
cross-bands. In the adults the tail was colored like the body. The
specimen from 14 kilometers south-southwest of Apatzingán (KU 29764) and
those from Cofradía (BMNH 1914.1.28.28-30) were not listed by Dixon
(1960).

Phyllodactylus homolepidurus Smith

These specimens have been referred to Phyllodactylus homolepidurus by
James R. Dixon (in litt.), who is currently studying the American
members of the genus. Geckos of this species have been found in tropical
semi-deciduous forest in the coastal lowlands to elevations of 500
meters. Most specimens were found beneath the bark of standing dead
trees or stumps. Two individuals from El Ticuiz (UMMZ 115102) in life
were dark gray above with brownish tubercles; the belly was a dusty
cream-color. Apparently this species does not enter the Tepalcatepec
Valley, where Phyllodactylus lanei is abundant.

Phyllodactylus lanei Smith

This widespread species has been taken at elevations of less than 1100
meters in the Balsas-Tepalcatepec Basin, where it occurs in[Pg 60] riparian
situations in the foothills. Specimens have been collected in tropical
semi-deciduous forest at Ostula and in oak forest south of Arteaga; both
of these localities are on the Pacific slopes of the Sierra de
Coalcomán, a region inhabited by Phyllodactylus homolepidurus. Both
species have been collected at Ostula.

A juvenile from 21 kilometers south of Arteaga (UMMZ 118933) had
alternating black and white bands on the tail. In life most of the
lizards are dull ashy gray or grayish tan above and white below.
According to Dixon (in litt.), one specimen from Apatzingán (UMMZ
115102) resembles Phyllodactylus magnus in scutellation, but it lacks
the distinctive yellow venter of that species.

Apparently Phyllodactylus lanei is restricted to rather mesic
environments in the Balsas-Tepalcatepec Valley and surrounding
foothills; in the more open arid environments on the floor of the valley
it seems to be replaced by Phyllodactylus duellmani.

Phyllodactylus paucituberculatus Dixon

Two of these specimens (UMMZ 112692-3) were discussed in detail by Dixon
(1960:40) in his description of the species. On August 25, 1960, Dixon
collected four additional specimens at the type locality, a conglomerate
cliff along the Río Marquez. These will be reported by him in his
forthcoming study of the genus.

Anolis dunni Smith

Three females from Arteaga (UMMZ 119075) have snout-vent lengths of 41,
41, and 44 mm. In life the pale grayish brown dorsum was marked with
dark brown; the belly was white, and the throat was pale pink. All have
a dark interorbital bar and dark vertical bars on the upper labials. In
two specimens there are only scattered dark flecks on the dorsum; in the
third there is a dark postorbital stripe, a dark lateral stripe, and
four narrow transverse bands on the body. A male from 19 kilometers
south of Arteaga (UMMZ 119076) having a snout-vent length of 49 mm. had
in life a tan dorsum, a broad white stripe from the ear to the groin,
scattered small white spots on the dorsum, and indistinct pale
cream-colored spots on the posterior surfaces of the thighs. This male
has the dark labial bars,[Pg 61] but lacks the dark interorbital bar, found in
the females. The large rose-pink throat fan extends to about the middle
of the belly. In all of the specimens the middorsal scales are keeled
and much smaller than the smooth pavementlike or slightly imbricate
ventrals. All have two gulars in contact with the mental, five scales
between the nasals, five scales (not including the first labials) in
contact with the rostral, and four rows of loreals. In these characters
these specimens agree well with Anolis dunni from Guerrero, as
diagnosed by Davis (1954b).

Previously Anolis dunni has been reported only from the vicinity of
Agua del Obispo, Guerrero, a locality situated at an elevation of about
900 meters in pine-oak forest in the Sierra del Sur. All known close
relatives of Anolis dunni occur only in Guerrero: A. taylori Smith
and Spieler from Acapulco, A. gadowi Boulenger from Tierra Colorado,
A. liogaster Boulenger, and A. omiltemanus Davis from Omiltemi. The
present specimens from elevations of about 900 meters in riparian stream
vegetation and oak forest represent the northern known limits of this
group of Anolis.

Anolis nebulosus (Wiegmann)

Even with the abundance of material the assignment of a specific name to
these anoles is only tentative, for definite determination between
Anolis nebulosus Wiegmann and A. nebuloides Bocourt is uncertain.
Bocourt (1873:75) distinguished A. nebuloides from A. nebulosus by
the following characters: (1) head scales keeled, not smooth; (2) snout
narrower; (3) ear opening larger; (4) supraorbital semicircles separated
by a row of small scales and not in contact; (5) dorsal scales larger
and subequal in size to the belly scales. Boulenger (1885:77) used the
same characters; Smith and Taylor (1950b:58) in their key to the Mexican
species[Pg 62] of Anolis stated that the dorsal scales are slightly smaller
than the ventrals in A. nebulosus and markedly smaller in A.
nebuloides. Smith (in litt.) stated that the characters of the
relative sizes of the dorsal and ventral scales were incorrect in that
key.

The application of the above criteria to specimens from Michoacán has
not resulted in the recognition of two species. The majority of the
specimens have the supraorbital semicircles separated by at least one
small scale; the head scales, with the exception of those on the snout
in a few individuals, are smooth; the dorsal scales are only slightly
smaller than the ventrals. In other characters of scutellation the
specimens are highly variable. The males in life have an orange throat
fan. Anoles of this kind have been found in Michoacán, Colima, Jalisco,
Nayarit, and southern Sinaloa. Near Oaxaca, Oaxaca, specimens were
collected that superficially resemble those from Michoacán and farther
north. These have low keels on the snout scales, dorsals somewhat larger
than the ventrals, and a pink throat fan. In ten males from Oaxaca the
size of the dorsal scales relative to that of the ventrals is 1.00:0.83;
the same ratio for 25 males from Michoacán is 1.00:1.08. In both samples
there are specimens in which the dorsal and ventral scales are about
equal in size.

Investigations by Richard E. Etheridge on the osteology of Anolis,
including those species here being considered, have revealed relatively
constant differences in the parasternalia and in the caudal vertebrae.
The application of Etheridge’s findings to anoline systematics must
await the completion of his study.

The carination of the scales on the snout versus smooth scales there
seems to be the only significant character given by Bocourt that
distinguishes A. Nebuloides from A. nebulosus. The difference in the
color of the throat fan, which is apparent only in living individuals,
is more striking. Obviously more than one species is represented, as is
borne out by the differences in the color of the throat fan and in the
osteology, but there is uncertainty about the correct name for each
species. On the strength of Bocourt’s diagnosis of keeled snout scales
in A. nebuloides, I am applying that name to the population in Oaxaca
and A. nebulosus to the specimens from Michoacán. As arranged here,
the two species can be distinguished, as follows:

[Pg 63]

With respect to geographic distribution, A. nebulosus has been
collected from southern Sinaloa southward to Michoacán. The lizards here
referred to A. nebuloides have been taken only in pine-oak forest on
the mountain slopes near Oaxaca City. Zweifel and Norris (1955:233)
reported anoles with pink throat-fans from southern Sonora; possibly
those specimens are A. nebuloides; I have not examined them. I have
seen several preserved specimens from the vicinity of Tehuantepec,
Oaxaca. Although they probably belong to this group, those specimens
differ from both A. nebulosus and A. nebuloides in their larger
size, relatively larger head, and much larger throat fan.

Aside from the minor variation in scutellation, specimens of Anolis
nebulosus from Michoacán vary greatly in coloration. Usually the
females have some form of a broad middorsal pale-colored band. In life
this is dull yellow, tan, or orange. Two females from Dos Aguas are
strikingly different; one (UMMZ 119521) has a broad middorsal orange
stripe that is scalloped laterally and bordered by gray. The other (UMMZ
119081) has a narrow middorsal cream-colored line. Males usually are
unicolor brown or olive-tan; sometimes the middorsal region is darker.
Some individuals have dark cross-bands or chevrons on the dorsum. One
male from Dos Aguas (UMMZ 119080) has a cream-colored lateral stripe.

In Michoacán Anolis nebulosus occurs from sea level to elevations
slightly in excess of 2100 meters, usually in areas of dense cover,
whether this be herbaceous, viney, or woody, ordinarily on the ground as
well as in bushes and trees. One was in a bromeliad growing about ten
meters above the ground. In the arid Tepalcatepec Valley anoles of this
species are most frequently found in the tangled growth along streams.
Above Uruapan they were found in pine-oak forest, and on the Mexican
Plateau between Zamora and Zacapu they were found in a bunch grass-scrub
oak association.

Anolis schmidti Smith

Peters (1954:11) reported on the specimen from La Placita; another was
secured at San Juan de Lima in 1956. The latter (UMMZ 115078) is a male
having a snout-vent length of 43.0 mm. and a tail length of 70.5 mm. The
dorsal ground color is pale tan; there are five pairs of irregular dark
brown dorsolateral blotches. In life the throat fan was pale orange.
These specimens agree with those from[Pg 64] Colima described by Duellman
(1958c:10). The distribution of Anolis schmidti seems to be restricted
to the coastal lowlands from Michoacán to Nayarit.

Basiliscus vittatus Wiegmann

This species has been found only on the coast and in the low
Tepalcatepec Valley. In the latter area it is restricted to riparian
situations along the larger streams. The lizard is abundant in the
mangrove swamps bordering the brackish lagoons on the coast. In July,
1955, scores of individuals were seen around Estero Pichi at Playa Azul.
Adults, especially the large males, are exceedingly wary and difficult
to collect. At all localities where they were found, the lizards were
most often seen in dense bushes, where they are well camouflaged.
Individuals of all sizes were observed to run across the surface of the
ponds.

Iguana iguana rhinolopha Wiegmann

Like the preceding species, this lizard is always found near water. It
does not ascend the foothills of the Sierra de Coalcomán, but in the
Balsas Basin it reaches elevations of 800 meters at La Playa. Large
adults are often seen in the large trees making up the gallery forests
along rivers. From high perches the lizards drop into the water with a
terrific splash. Bright green juveniles were abundant in bushes along
the Río Tepalcatepec in July, 1955.

Ctenosaura pectinata (Wiegmann)

[Pg 65]

Ctenosaura pectinata is a common lowland species that ascends the
slopes of the Sierra de Coalcomán and the Cordillera Volcánica to
elevations of about 1050 meters (approximating the lower limits of the
oak forest). The record from Uruapan (USNM 10234, collected by Dugès) is
doubtful.

These large lizards are most easily observed on rock fences along roads.
Near Apatzingán innumerable individuals can be seen in mid-morning.
Later in the day, as the sun rises higher in the sky, the lizards
retreat to the shade of the crevices in the fences. The abundance of
these lizards in the Tepalcatepec Valley, together with evidence
gathered from the natives of the valley, indicates that these lizards
are seldom used for human consumption there. On the other hand, several
people in Coalcomán consider the “iguana negra” (local name for
Ctenosaura) to be a delicacy and serve it at every opportunity. In
early July, 1951, brilliant green young of the year were collected at La
Playa and at Coalcomán.

Enyaliosaurus clarki (Bailey)

This species is known only from the low areas of the Balsas-Tepalcatepec
Basin between elevations of 200 and 510 meters. It is commonly found in
the open arid tropical scrub forest dominated by Prosopsis sp.,
Apoplanesia paniculata, and Cercidium plurifoliolatum. Continued
collecting in the Tepalcatepec Valley has borne out the suggestions of
Duellman and Duellman (1959) concerning the distribution and abundance
of this lizard. Also, continued collecting in Colima and on the Pacific
coast has failed to reveal the presence of Enyaliosaurus there.

Phrynosoma asio Cope

In Michoacán this species has been obtained only in the Tepalcatepec
Valley and on the northern slopes of the Sierra de Coalcomán between 300
and 700 meters. Apparently the lizard is absent from the coastal
lowlands of Michoacán and Guerrero. The distribution of this species,
therefore, is discontinuous. One population[Pg 66] inhabits the lowlands of
Colima and the Balsas-Tepalcatepec Basin inland to northern Guerrero and
Morelos; a southern population inhabits the Plains of Tehuantepec in
Oaxaca.

A juvenile from Apatzingán (USNM 47739) has a snout-vent length of 40.0
mm. and a tail length of 19.5 mm.

Sceloporus aeneus aeneus Wiegmann

This small terrestrial species inhabits the pine and fir forests of the
Cordillera Volcánica between elevations of 1850 and 3100 meters;
apparently it is absent from the Sierra de Coalcomán. It seems to prefer
rather open coniferous forests in which there is a more or less
continuous cover of grasses on the ground. On warm sunny days the
lizards can be observed scurrying about in the grass; in the early hours
of the day, or on cold days, they are found beneath stones, logs, or
dead clumps of bunch grass.

Sceloporus asper Boulenger

This strictly arboreal lizard is abundant in the mixed broad-leafed
forest near Uruapan. The lizards are exceedingly wary and can be
approached only with difficulty. In life males have pale blue bellies;
the throat is pale pink. The pale gray dorsum marked with irregular
darker gray blotches blends well with the color of the tree trunks on
which the lizard lives. The one specimen from Dos Aguas was found on a
pine tree; it provides the only record for the species from the Sierra
de Coalcomán.

Sceloporus bulleri Boulenger

Heretofore this species has been known only from a few specimens from
scattered localities in the Sierra Madre Occidental in[Pg 67] southwestern
Jalisco and Sinaloa. The collection of a large series of these lizards
in virgin pine forest at elevations of more than 2000 meters in the
Sierra de Coalcomán now makes possible an analysis of variation in the
species.

Superficially S. bulleri resembles S. torquatus, but S. bulleri is
smaller, has more dorsal scales, fewer scales in the dark collar, and
fewer femoral pores. In 88 specimens of S. bulleri there are 36-41
(38.7) dorsal scales and 2 or 3 (2.6) middorsal scales in the collar, as
compared with 28-31 (29.3) dorsal scales and 3 or 4 (3.4) middorsal
scales in the collar of 26 specimens of S. torquatus from Uruapan. In
20 adult males of S. bulleri there are 13-15 (14.3) femoral pores, and
13-16 (14.4) in 11 females; 13 males of S. torquatus have 14-21 (17.3)
femoral pores, and 13 females have 15-21 (16.7). Seventeen adult males
of S. bulleri have snout-vent lengths of 72-91 (82.0); ten females,
71-87 (75.7). In comparison, 13 adult males of S. torquatus have an
average snout-vent length of 88.9 mm., and 13 females, 88.5 mm. In S.
bulleri there is little variation in the head scales. The frontal is in
contact with the interparietal in 63, and not in 24, specimens; the
median frontonasal is in contact with the frontal in 13, and not in 74,
specimens. In 39 specimens there are two canthals, and in 48 there is
one; in 29 specimens there are three preauriculars, and in 58 there are
four.

In life adult males have a pale blue tail, bright blue belly patches, a
purplish blue throat, and pale blue lines on the sides of the head and
neck.

This species was obtained at four localities in the high mountains of
the Sierra de Coalcomán. In this mountain range Sceloporus bulleri
apparently replaces S. torquatus, a species that is widespread in the
Cordillera Volcánica and on the Mexican Plateau. At Dos Aguas and at
Acuaro de las Lleguas the lizards were abundant in the tall pine forest,
where they were found on standing pine trees, on pine logs, and on rock
outcroppings.

Sceloporus dugesi intermedius Dugès

This lizard is strictly an inhabitant of the Mexican Plateau, where it
is found in rocky places, sometimes in pine-oak forest,[Pg 68] but more
frequently in mesquite-grassland. It is a terrestrial species, and is
most often seen on rock fences at elevations of 1500 to 2200 meters.

This species differs from S. bulleri and S. torquatus in having two
rows of supraoculars, instead of one; also it has more dorsal scales.
Twenty-six specimens of Sceloporus dugesi intermedius from
Tangamandapio and Tangancícuaro have 44-48 (45.7) dorsal scales, as
compared with an average of 38.7 in S. bulleri and 29.3 in S.
torquatus. In life Sceloporus dugesi intermedius has a dull greenish
gray dorsum; in males the belly patches are bright blue bordered
medially by black, and the throat is bluish gray. The largest specimen
examined is a male having a snout-vent length of 80 mm.

Sceloporus gadowae Boulenger

Although this species has a rather extensive range in the
Balsas-Tepalcatepec Basin in the state of Michoacán, Guerrero, Morelos,
and Puebla, it is only locally abundant in that area. Usually these
lizards are found on rocky cliffs in which there are many crevices for
cover. Sceloporus gadowae is abundant on a conglomerate cliff along
the Río Marquez south of Lombardia. Although the closely related S.
pyrocephalus is abundant in the stream valley and in the hills above
the cliff, S. gadowae has been found only on the cliff; few
individuals of S. pyrocephalus have been observed on the cliff. A
similar situation was discovered on a much more extensive conglomerate
cliff along the Río Balsas near Mexcala, Guerrero. Near Tehuitzingo,
Puebla, where S. pyrocephalus was not found, S. gadowae was found on
conglomerate cliffs. Probably there is strong competition between the
two species; possibly this has resulted in the restriction of S.
gadowae to isolated cliff-habitats within the extensive range of the
more widespread S. pyrocephalus.

In Michoacán Sceloporus gadowae has been found along the lower slopes
of the Cordillera Volcánica at elevations from 250 to 1050 meters. All
of the localities from which this lizard is known lie in the arid
tropical scrub forest.[Pg 69]

Sceloporus grammicus microlepidotus Wiegmann

This small species of Sceloporus is an ubiquitous inhabitant of the
coniferous forests from 1550 to 3100 meters in the Cordillera Volcánica.
Usually it is seen on tree trunks, but occasionally on the ground. Near
the lower limit of the altitudinal distribution of the species, as at
Uruapan, individuals sometimes are found on broad-leafed trees.
Apparently Sceloporus heterolepis replaces S. grammicus
microlepidotus in the Sierra de Coalcomán.

Sceloporus heterolepis Boulenger

Although Michoacán has not previously been included in the range of this
lizard, it was first collected in the state by Gadow in 1908 (BMNH
1914.1.28.69 from Araparicuaro). The description of S. heterolepis
given by Smith (1939:197) can be supplemented by data on the 23
specimens now in the collections of the Museum of Zoology at the
University of Michigan. All have two canthals; there are 55 to 71 (63.6)
scales in the middorsal row; 1 to 3 rows middorsally are somewhat
enlarged and bordered on either side by a row of larger scales bearing
high keels. There are 14 to 20 (16.2) femoral pores. Eight adult males
have snout-vent lengths from 49 to 61 (58.0) mm. and tail lengths from
57 to 74 (66.0) mm.; four adult females have snout-vent lengths from 52
to 57 (55.2) mm. and tail lengths from 60 to 66 (63.5) mm. The smallest
of eight juveniles has a snout-vent length of 28 mm. and a tail length
of 32 mm. The dorsum in adults is pale grayish brown; there are three
irregular chevron-shaped dark marks and a triangular dark brown mark
above the insertion of the hind limbs; on the tail are dark brown rings.
There are scattered faint blue flecks on the flanks and narrow
transverse dark lines on the lower limbs. Males[Pg 70] have pale bluish green
belly patches and an orange-salmon-colored throat; the belly in females
is pale orange-tan. The juveniles have a more contrasting color pattern;
the dark chevrons on the dorsum are bordered posteriorly by pale gray.

In Michoacán this species has been obtained in pine and pine-fir forests
from 1800 to 2700 meters. On Cerro Barolosa and at Dos Aguas, both in
the Sierra de Coalcomán, the lizards were found beneath the bark of
dead, standing pines. In the Sierra de Coalcomán Sceloporus
heterolepis seems to fill the niche of the small arboreal Sceloporus
in the coniferous forest in southwestern México, a position held by S.
grammicus microlepidotus in the Cordillera Volcánica; the latter
species does not occur in the Sierra de Coalcomán. Five specimens of
Sceloporus heterolepis are known from the Cordillera Volcánica,
whereas 603 of S. grammicus microlepidotus have been collected there.
The ecological relationships that exist between the two species in the
Cordillera Volcánica are not known.

Insofar as is known, Sceloporus heterolepis reaches the southern
limits of its range in the Sierra de Coalcomán and in the western part
of the Cordillera Volcánica. Other records for the species are from the
Sierra Madre Occidental in Jalisco. Langebartel (1959) described
Sceloporus shannonorum from the mountains near the Durango-Sinaloa
border; the single specimen of S. shannonorum differs significantly
from S. heterolepis only in having fewer dorsal scales (48). The
acquisition of additional material, especially from Nayarit and northern
Jalisco, probably will provide a basis for showing that these two
populations are conspecific.

Sceloporus horridus oligoporus Cope

All of the specimens from Michoacán seem to be typical S. horridus
oligoporus; none has more than six femoral pores.

Characteristically this species is found in open arid scrub forest; it
reaches its greatest abundance in rocky areas in which there are
scattered leguminous trees and bushes. It has been found in these[Pg 71] low
trees and bushes almost as frequently as it has been found on the
ground; none has been seen in large trees or far above the ground.
Altitudinally, this species ranges from sea level to about 1600 meters.

Sceloporus melanorhinus calligaster Smith

Smith (1942a:360) diagnosed Sceloporus melanorhinus calligaster as
having fewer femoral pores than the other subspecies of S.
melanorhinus and as having the lateral belly patches in the males
confluent in the midline. Examination of forty specimens from the
Tepalcatepec Valley and the coastal regions of Michoacán does not
substantiate this diagnosis. The number of femoral pores varies from 15
to 22 (18.9); 14 individuals (35%) had 20 or more femoral pores. Smith
(loc. cit.) stated that S. melanorhinus in Oaxaca had 18 to 27
(21.6) femoral pores and that 77 per cent of the specimens had more than
20 femoral pores. Of the 24 males examined from Michoacán, 18 have the
lateral belly patches separated in the midline. Usually they are
separated by no more than one scale, but in some individuals they are
separated by two or more scales. Although the above data minimize
certain differences between the northern and southern populations of
this species, certain of the color pattern characters seem to be
diagnostic of the subspecies inhabiting the Pacific lowlands from
Guerrero to Nayarit. Large adults of S. m. calligaster have only a
faint dorsal pattern, which in the subspecies melanorhinus and
stuarti consists of a series of large, dark, interconnected triangles
on the back. This pattern is present in young and small adults of S. m.
calligaster; furthermore, in this subspecies the ventral coloration of
the males differs from that found in the more southern populations.
Adult males of S. m. calligaster have a black throat, that changes to
brilliant blue posteriorly, and a large white spot medially on the chin.
This spot is present in some specimens from Oaxaca and Chiapas, but, if
present, it is much smaller and less distinct than in specimens from
Michoacán. In S. m. calligaster the chest and midventral area are
orange to salmon-color.

A male from Lombardia in life was colored as follows: Dorsum grayish tan
bearing faint bluish gray flecks; chest deep salmon-orange,[Pg 72] this color
continuing down midventral area to the somewhat paler groin; belly
patches pale blue fading to pale green laterally; throat black
anteriorly enclosing a white spot; throat blue posteriorly and bluish
green posterolaterally.

Individual lizards were observed to change in dorsal color from a pale
ashy gray to a rather dull brown. Normally, inactive individuals and
those observed on overcast days were dull brown.

Sceloporus melanorhinus calligaster is found in trees in riparian
situations in the lowlands to elevations of about 1500 meters. It does
not inhabit the arid tropical scrub forest in the Tepalcatepec Valley or
on the coast, but in those areas is found in the gallery forests along
streams and rivers. The lizards are wary and live high in the trees;
they are especially difficult to locate in the rainy season, when the
trees are in full leaf.

Sceloporus pyrocephalus Cope

This small species is extremely common in the Tepalcatepec Valley and
noticeably less so on the coast. It is usually found on the ground in
rocky areas, but males frequently have been seen on the trunks of low
trees in the scrub forest. Altitudinally, it ranges from sea level to
slightly more than 1000 meters. The sexes are readily distinguished in
the field (Oliver, 1937; Smith, 1939; Duellman, 1954b). In the dry
season only males were observed in the Tepalcatepec Valley, but in the
rainy season both sexes were found in approximately the same numbers.

Sceloporus scalaris scalaris Wiegmann

This small terrestrial species does not seem to be abundant anywhere in
the state. It sometimes is found in open pine, oak, or[Pg 73] pine-oak forest,
but usually it is observed in areas supporting bunch grass. In such
places the lizards sun and forage on the open ground and quickly take
refuge in the large clumps of grass. Altitudinally, the species ranges
from 1550 to 2300 meters. Although Sceloporus scalaris scalaris has
been found in association with S. dugesi intermedius, S. spinosus,
and S. torquatus, it does not seem to form any close ecological
association with any of these species. In the pine forests of the
Cordillera Volcánica S. s. scalaris is replaced by Sceloporus aeneus
aeneus, another small terrestrial species that occurs in great
abundance throughout the coniferous forests of the Cordillera Volcánica.

Sceloporus siniferus siniferus Cope

This small terrestrial species inhabits the dense arid tropical scrub
forest on the coast and lower foothills of the Sierra de Coalcomán to
elevations of about 150 meters. It also occurs in the lower Balsas
Valley, but it has not been found in the scrub forest of the broad
Tepalcatepec Valley. Perhaps the large number of Sceloporus siniferus
on the coastal lowlands is responsible for the small number there of S.
pyrocephalus, another terrestrial species of about the same size. The
latter is abundant in the Tepalcatepec Valley, where S. siniferus
siniferus has not been found. Sceloporus siniferus siniferus is a
fast runner and difficult to collect; consequently, the small number of
specimens available is not indicative of its abundance.

Sceloporus spinosus spinosus Wiegmann

Although this species is widespread on the southern part of the Mexican
Plateau, it is uncommon in Michoacán. It has been collected[Pg 74] only in
rather open situations in the mesquite-grassland on the plateau between
1500 and 2300 meters, where it has been found in association with
Sceloporus dugesi intermedius and S. scalaris scalaris. Most
specimens of Sceloporus spinosus spinosus have been observed on rock
fences. In this habitat the species is the larger member of a pair of
species, the smaller of which is Sceloporus dugesi intermedius.

Sceloporus torquatus torquatus Wiegmann

This large species inhabits the Mexican Plateau and the Cordillera
Volcánica, but not the Sierra de Coalcomán, where apparently it is
replaced by Sceloporus bulleri. Sceloporus torquatus torquatus
usually is found in pine or pine-fir forests at elevations between 1450
and 3000 meters. In many places it is almost entirely arboreal, but in
areas where there are many fallen trees or rock fences and rock piles,
many individuals have been found on the ground near the rocks or logs.
In the coniferous forests this species is associated with S. grammicus
microtepidotus and S. aeneus aeneus.

The distinction made by Smith (1938:572) between the subspecies S.
torquatus torquatus and melanogaster is slight. Individuals with pale
bluish spots are found throughout the range of the species in Michoacán;
spotting is especially evident in the young. Individuals having an
incomplete nuchal collar have been found at Maravatio and at Zinapécuaro
in the northern part of the state; in this character these specimens
resemble S. torquatus melanogaster, which is found to the north from
Guanajuato to Zacatecas and San Luis Potosí.[Pg 75]

Sceloporus utiformis Cope

In Michoacán the range of this species is discontinuous. It has been
found between 1050 and 1550 meters on the slopes of the Cordillera
Volcánica, and on the coast and seaward slopes of the Sierra de
Coalcomán up to an elevation of 900 meters. It is absent from the
Tepalcatepec Valley. At Uruapan and at Cascada Tzararacua this lizard
was found on the ground in oak forest or in open pine-oak forest; on the
coast and foothills of the Sierra de Coalcomán it was found on the
ground in the gallery forests along streams, and not in the scrub
forest.

Urosaurus bicarinatus tuberculatus (Schmidt)

The known distribution and geographic variation of Urosaurus
bicarinatus in southwestern México presents a confused picture. In
general rugosity, specimens from the coastal region of Michoacán
(Coahuayana, La Orilla, La Placita, Playa Azul, and Pómaro) resemble U.
bicarinatus tuberculatus to the north along the Pacific coast.
Furthermore, specimens from the coast have less stippling in the gular
region than do those from the Sierra de Coalcomán and the slopes of the
Cordillera Volcánica. Specimens from the mountains have greatly carinate
enlarged dorsals, large lateral tubercles, and heavily stippled throats;
in these characters they resemble specimens from Morelos, Guerrero, and
Oaxaca. As mentioned by Peters (1954:14), some specimens from La Orilla
and San Salvador are like U. bicarinatus bicarinatus in certain
characters, and one specimen has the blue ventral patches restricted to
the sternal area, a characteristic of U. bicarinatus anonymorphus of
Oaxaca and eastern Guerrero. Examination of all available specimens from
Michoacán indicates that the nature of the dorsal scales is of little
value in separating the subspecies. The specimens from Michoacán are
here provisionally referred to U. bicarinatus tuberculatus,[Pg 76] because
cursory examination of specimens from several localities between Nayarit
and Oaxaca shows that there are only minor differences between the named
populations. Individuals from the northern part of the range are more
rugose and have larger blue ventral patches and less gular stippling
than those from the south.

In Michoacán Urosaurus bicarinatus tuberculatus is found in wooded
areas, not in open scrub forest, in the coastal area to elevations of
about 900 meters, and along the slopes of the Cordillera Volcánica and
the southern edge of the Mexican Plateau at elevations from 1000 to 1700
meters. The record for Tupátaro probably is erroneous, for no other
specimens of this species are known from the central plateau.
Essentially, the distribution of this species parallels that of
Sceloporus utiformis, a strictly terrestrial species. Urosaurus
bicarinatus tuberculatus lives on tree trunks. Below 1000 meters in the
Tepalcatepec Valley Urosaurus bicarinatus tuberculatus is replaced by
Urosaurus gadowi.

Urosaurus gadowi (Schmidt)

Although individuals of this species have been collected at elevations
slightly exceeding 1200 meters on Volcán Jorullo and at 1100 meters at
Ziracuaretiro on the southern slopes of the Cordillera Volcánica, for
the most part these lizards are found at elevations of less than 800
meters, where they inhabit the open arid scrub forest of the
Tepalcatepec Valley, a region to which this species is endemic
(Duellman, 1958b:49). These small lizards usually are found on the
trunks and main branches of the small trees in the scrub forest; in this
habitat they are associated with Sceloporus horridus oligoporus, a
much larger species.

Males have a pale orange spot on the throat and a pale blue belly;
females have immaculate venters.

A specimen from Guayabo on the northern slopes of the Sierra de
Coalcomán was referred to Urosaurus irregularis (Fischer) by Peters[Pg 77]
(1954:15). I have studied this specimen (BMNH 1914.1.28.110), a female
having a snout-vent length of 46 mm., and agree with Peters that it
closely resembles Fischer’s description and figure (1882: pl. 17, fig.
1). This specimen and those seen of Urosaurus gadowi all have
pavementlike enlarged dorsal scales that are complete across the
vertical line. In U. gadowi the enlarged dorsals usually are in four
to six irregular rows; in the specimen from Guayabo the dorsals are in
two rows. Although none of the other specimens of U. gadowi examined
has only two rows of enlarged dorsals, I prefer to consider the specimen
from Guayabo as an aberrant individual of that species, rather than U.
irregularis. Guayabo is in the known range of U. gadowi. Urosaurus
irregularis is known only from the type specimen in the Bremen Museum;
the type locality, according to Fischer (1882:232), is “Aus dem
Hochlande von Mexico.” If an examination of the type specimen of U.
irregularis shows it to be identical with U. gadowi, then U.
irregularis would be the name for the lizards here referred to U.
gadowi.

Mabuya brachypoda Taylor

Previously this species has been reported from La Placita as Mabuya
mabouya alliacea by Peters (1954:15). Webb (1958:1311) provided
evidence that Mexican specimens were conspecific with Mabuya
brachypoda, as described from Costa Rica by Taylor (1956:308). The
large series in the Taylor collection studied by Webb and listed by him
as being from Uruapan actually is part of a series collected by Hobart
M. Smith at El Sabino at an elevation of 1050 meters, 30 kilometers
south of Uruapan.

This species probably ranges throughout the coastal region of the state;
individuals from La Placita and Playa Azul were taken in dense scrub
forest near sea level.

Scincella assata taylori (Oliver)

The specimen from Ostula was obtained in semi-deciduous broad-leaf
forest at an elevation of 120 meters; that from 21 kilometers south of
Arteaga was taken in oak forest at an elevation of 830 meters.[Pg 78] Both
localities are on the coastal slopes of the Sierra de Coalcomán.
Probably the species inhabits the heavy forests on the lower slopes of
these mountains. The specimen from south of Arteaga (UMMZ 119117) in
life had a tan dorsum and a bright orange-pink tail.

Eumeces altamirani Dugès

One specimen of this rare species was found beneath a rock in the open
scrub forest 12 kilometers east of Apatzingán on July 3, 1955. Another
skink, presumably of this species, was seen at Capirio. The specimen
from east of Apatzingán is a male having a snout-vent length of 97 mm.
and an incomplete tail. In most respects it compares favorably with
accounts of the species given by Taylor (1936b:55 and 1936c:102). The
frontal is divided by a transverse suture; the enlarged dorsal scales
are arranged in 11 pairs anteriorly, followed by 48 unpaired enlarged
scales. The head and middorsal area are brown; there is a pale tan
stripe on the edges of the vertebral and paravertebral rows, bordered by
a dark brown stripe on the paravertebral row, which, in turn, is
bordered by a pale tan stripe on the lateral edge of the paravertebral
scale row and the median edge of the adjacent scale row. The stripes
extend from the neck to the base of the tail. The flanks are mottled
with brown and cream-color; the labials are cream-color barred by brown;
the venter is a pale cream-color.

Dugès (1891:485) described Eumeces altamirani from “las regiones
cálidas del Estado de Michoacán” and subsequently (1896:480) gave
Apatzingán as a locality for the species. Presumably he had only one
specimen. In 1935 Hobart M. Smith collected the species at El Sabino on
the lower slopes of the Cordillera Volcánica bordering the Tepalcatepec
Valley. All of the known specimens are from this valley and the adjacent
slopes, an area to which the species apparently is endemic.

Eumeces colimensis Taylor

The species was reported by Peters (1954:16); no additional material has
been discovered. The species is known only from foothills and low
mountains at elevations between 130 and 950 meters in Michoacán and
Colima.[Pg 79]

Eumeces copei Taylor

This member of the Eumeces brevirostris-group has been found only in
pine or pine-fir forests at elevations from 1800 to 2700 meters. It
probably ranges throughout the high mountains of the state north of the
Tepalcatepec Valley; its apparent absence in other parts of the
Cordillera Volcánica, other than on Cerro Tancítaro, is surprising. The
species has been taken near Asunción in the state of México and at
Lagunas de Zempoala in Morelos.

In this species the lateral pale yellow stripe, which is bordered below
by dark brown, extends to the groin and onto the base of the tail. The
dorsolateral stripe is separated from the copper-colored middorsum by a
narrow brown stripe.

Eumeces dugesi Thominot

Individuals of this species frequently have been found beneath rocks and
logs in pine-oak, pine, or fir forests from elevations of 1550 to 1850
meters. To judge from specimens available, E. dugesi probably is the
most abundant and widespread species of skink in the state.

In this species the lateral yellow stripe is indistinct and is
persistent only in the axilla; the dorsolateral stripes terminate
anterior to the hind limbs and are not separated from the tan dorsum.

Eumeces indubitus Taylor

The one specimen of this species from Michoacán was collected by Edward
H. Taylor in pine forest at Puerto Hondo, near Zitácuaro, at an
elevation of about 2750 meters (Taylor, 1935:466). The species is known
from the high mountains of eastern Michoacán, western México, and
northern Morelos.[Pg 80]

Eumeces parvulus Taylor

Aside from the specimens reported by Peters (1954:17), one other
specimen was obtained at El Ticuiz. It has 22 scale rows, 3 supraoculars
in contact with the frontal, 2 postlabials, and a unicolored olive-tan
dorsum. In life the anterior dorsolateral stripes were pale pinkish tan,
the labials cream color, the throat white, and the tail pale blue. All
specimens were found in semi-deciduous broad-leaf forest at elevations
of less than 500 meters on the seaward slopes of the Sierra de
Coalcomán.

Ameiva undulata sinistra Smith and Laufe

Six males and six females from the Tepalcatepec Valley have more femoral
pores than do 16 males and nine females from the coastal lowlands; the
ranges and average number of femoral pores in the former are 40-50
(44.8) for males and 38-40 (38.6) for females; males from the coast have
34-44 (39.2), and females have 32-40 (36.2) femoral pores. In all
specimens the number of lamellae beneath the fourth toe varies from 26
to 33 (29.7). In life juveniles have a pale olive-tan dorsum and a
dorsolateral dark band, superimposed on which is a row of darker brown
spots. The dorsolateral band is bordered below by a narrow cream-colored
stripe. The tail is tan above and grayish white below; the belly is pale
bluish white. Adult males are brilliantly colored in life. A male having
a snout-vent length of 108 mm. had a rusty brown dorsum and bright blue
bars on the flanks separated by dark brown interspaces. The side of the
head was pale green, and the chin and throat were golden yellow. In some
specimens the throat is orange. Juveniles and subadults have dark flecks
on the brown or tan middorsal area, but these are absent in the largest
males.

This species inhabits the heavily wooded areas in the lowlands to
elevations of about 950 meters. In the Tepalcatepec Valley it has been
found only in gallery forests along streams. In both the Tepalcatepec
Valley and the coastal lowlands there is a noticeable absence of large
adults in the dry season.[Pg 81]

Cnemidophorus calidipes Duellman

This small, distinctive species of the sexlineatus-group of
Cnemidophorus was discovered in the Tepalcatepec Valley in 1955
(Duellman, 1955); subsequent field studies showed it to be widespread in
the valley (Duellman, 1960c). One specimen (KU 29747) is from the
relatively arid, low Pacific slope of the Sierra de Coalcomán, 25
kilometers south of Arteaga. All other specimens have been taken at
elevations of 200 to 650 meters in the Tepalcatepec Valley, where the
species characteristically inhabits the open scrub forests of the valley
floor, especially the Cercidium-Prosopis-Apoplanesia associations,
where there is a sparse growth of grasses. In this habitat it is most
frequently seen in association with Cnemidophorus costatus zweifeli
and C. deppei infernalis.

Aside from the characters given in Table 5, Cnemidophorus calidipes
differs from other species of Cnemidophorus in Michoacán by possessing
a complete (or nearly so) supraorbital semicircle-series of granules; in
other species the granules seldom extend anteriorly beyond the posterior
border of the frontal.

Cnemidophorus communis communis Cope

The specimens from Coalcomán and the coastal localities were referred to
Cnemidophorus sacki copei by Peters (1954:18) and Duellman (1954b:12).
Zweifel (1959a) referred these specimens to Cnemidophorus communis
communis and pointed out the probable sympatry of C. communis and C.
costatus (= sacki of Zweifel) in the Tepalcatepec Valley.

There is considerable geographic variation in the number of dorsal
granules around the midbody. Sixteen specimens from the coastal regions
of Michoacán have 129-146 (136.3) granules; nine from the Tepalcatepec
Valley have 124-137 (128.3), and 44 from Coalcomán at an elevation of
950 meters in the Sierra de Coalcomán, intermediate geographically
between the coast and the Tepalcatepec Valley, have 105-144 (119.7). The
number of granules in specimens from the coast of Michoacán compares
favorably with the range of 118-154 (137.8) for 34 specimens from
Colima, Colima (Zweifel, 1959a:107). Aside from the characters given in
Table 5, C. communis communis can be distinguished from other members
of the Cnemidophorus sexlineatus-group (calidipes, costatus, and
scarlaris) by its relatively small post-antebrachial scales.[Pg 82]

Table 5.—Comparison of the Ten Species and Subspecies of Cnemidophorus
in Michoacán (Scale Counts Are for Specimens from Michoacán Only)

[Pg 83]

Although this is the largest species of Cnemidophorus in Michoacán
(adult males attain a snout-vent length of 135 mm.), it is neither
widespread nor abundant. On the coastal lowlands it occurs primarily
with Cnemidophorus lineatissimus lividus. In the coastal lowlands
there is little open scrub forest, a type of habitat that seems to be
preferred by C. communis communis. In the Tepalcatepec Valley, C.
communis communis occurs in the open scrub forest with the more
abundant large species C. costatus (subspecies zweifeli). Only in
the scrub forest in the Coalcomán Valley, where no other species of
Cnemidophorus occurs, is C. communis communis abundant.

Cnemidophorus costatus occidentalis Gadow

Only four specimens from the extreme northwestern part of the state are
referable to this subspecies. These have 97 to 102 dorsal granules at
midbody and lack the blue gular band or spot characteristic of the
subspecies in the Tepalcatepec Valley. Probably C. costatus
occidentalis ranges throughout the Chapala depression, but to the east
it is replaced by Cnemidophorus scalaris scalaris.

Cnemidophorus costatus zweifeli Duellman

These lizards were referred to Cnemidophorus sacki copei by Duellman
(1954b:12 and 1955:6); Duellman (1960a) described the subspecies
zweifeli and assigned it to Cnemidophorus sacki. Zweifel (1961:98)[Pg 84]
used the specific name C. costatus for the whiptails on the
southwestern part of the Mexican Plateau (C. c. occidentalis). Since
occidentalis and zweifeli are conspecific, the combination C.
costatus zweifeli is used here for the population inhabiting the
Tepalcatepec Valley.

This lizard is abundant in the Tepalcatepec Valley, where it lives in
open and dense scrub forest, usually at elevations of less than 1000
meters. Throughout the valley it is found in association with
Cnemidophorus deppei infernalis, and in the lower parts of the valley
it also is associated with Cnemidophorus calidipes. Observations made
in the dry season indicate that large adults are not active at that
time.

On the coastal lowlands and in the valleys in the Sierra de Coalcomán
Cnemidophorus costatus zweifeli is replaced by C. communis communis.
To the east in the Balsas Basin C. costatus zweifeli intergrades with
C. costatus costatus.

Cnemidophorus deppei deppei Wiegmann

This small species, which is extremely abundant on the coastal lowlands
of Guerrero, seems to be rare on the coast of Michoacán, where it has
been taken at elevations of 130 and 500 meters in open situations in
otherwise forested areas. Duellman and Wellman (1960:25) discussed these
specimens in relation to their subspecific assignment. They were
referred to Cnemidophorus deppei lineatissimus by Peters (1954:18).

Cnemidophorus deppei infernalis Duellman and Wellman

This is one of the most abundant and widespread lizards in the
Tepalcatepec Valley. Throughout its range it is ecologically associated
with Cnemidophorus costatus zweifeli, which ranges to elevations
somewhat higher than the 1050 meters known for C. deppei infernalis.
This small lizard reaches its greatest abundance[Pg 85] in grassy areas on the
floor of the Tepalcatepec Valley, where in the
Cercidium-Prosopis-Apoplanesia associations it occurs with
Cnemidophorus calidipes.

Duellman and Wellman (1960) discussed the variation and relationships of
Cnemidophorus deppei, of which the subspecies infernalis is
restricted to the Balsas-Tepalcatepec Basin.

Cnemidophorus lineatissimus exoristus Duellman and Wellman

As in Cnemidophorus calidipes, the distribution of this subspecies
seems to be restricted to the Tepalcatepec Valley, except in the
vicinity of Arteaga, where it occurs on the southern slope of the Sierra
de Coalcomán. As pointed out by Duellman and Wellman (1960:46), the
specimens from south of Arteaga are like those from the Tepalcatepec
Valley in scutellation and coloration, and not like Cnemidophorus
lineatissimus lividus from the geographically closer coastal lowlands.

In the Tepalcatepec Valley Cnemidophorus lineatissimus exoristus
inhabits gallery forests along the larger streams; in this habitat it is
associated with Ameiva undulata sinistra. From the other species of
Cnemidophorus in Michoacán, C. lineatissimus exoristus can be
distinguished by the possession of seven longitudinal stripes in adults
and by the characters of scutellation given in Table 5.

Cnemidophorus lineatissimus lineatissimus Cope

These specimens have 117 to 126 dorsal granules at midbody, a noticeably
lower count than that for Cnemidophorus lineatissimus lividus on the
coast of Michoacán, which has 126 to 164 (148). Apparently these
specimens represent immature C. lineatissimus lineatissimus; the
differences between these and C. lineatissimus lividus from nearby
localities indicate that possibly the populations are distinct species
and not subspecies, as suggested by Duellman and Wellman (1960:41).[Pg 86]

Cnemidophorus lineatissimus lividus Duellman and Wellman

This is the most abundant and widespread species of Cnemidophorus on
the coastal lowlands of Michoacán, where it ranges from sea level to
elevations of about 500 meters. In this area it inhabits dense arid
scrub forest and semi-deciduous broad-leafed forest. Both of these
habitats are continuous, or nearly so, along the lowlands and foothills
of the Sierra de Coalcomán. This in itself may explain the abundance of
Cnemidophorus lineatissimus and the relative scarcity of C. deppei
and C. communis in the coastal area, for C. deppei and C. communis
usually inhabit more open arid scrub forest, as occurs in the
Tepalcatepec Valley. Living in the dense scrub forest with C.
lineatissimus is Ameiva undulata sinistra.

Cnemidophorus scalaris Cope

Zweifel (1959a:72) assigned the small species of Cnemidophorus having
a relatively low number of dorsal granules and inhabiting the southern
part of the Mexican Plateau to C. scalaris, which he diagnosed as
rarely exceeding 100 mm. in snout-vent length and always having an
average of less than 100 dorsal granules at midbody and usually less
than 90. Forty-two specimens from the south shore of Lago de Cuitzeo
(UMMZ 119558) have 80-91 (85.8) dorsal granules. Four specimens from 21
kilometers north of Norelia (UIMNH 6952 and UMMZ 104743) have 89, 78,
92, and 84 granules; one from Morelia (UMMZ 104742) has 78; two from
Araro (UMMZ 119522) have 80 and 87; one from Jacona (UIMNH 24703) has
88.

Since no large adult males are present in the series from Michoacán, an
adequate comparison of coloration between these and populations on the
northern part of the Mexican Plateau cannot be made. Cnemidophorus
scalaris is a name applied to the lizards inhabiting the Mexican
Plateau from Chihuahua south to Puebla by Zweifel (1959a:72). It is
doubtful if all of the populations[Pg 87] assigned to this subspecies belong
there; possibly more than one species is involved, but the paucity of
material prevents further analysis at this time.

Heloderma horridum horridum (Wiegmann)

This species is known from elevations of less than 1000 meters in the
Tepalcatepec Valley, the Sierra de Coalcomán, and the coastal lowlands.
Specimens from Coalcomán, La Placita, and Parácuaro came from areas of
dense woods; those from Apatzingán and Oropeo might have come from
patches of dense woods in the otherwise open scrub forest of the
Tepalcatepec Valley.

Gerrhonotus imbricatus imbricatus Wiegmann

Specimens from the Sierra de Coalcomán are noticeably different from
those inhabiting the mountains rising from the Mexican Plateau. Of 45
specimens from Cerro Tancítaro and adjacent areas on the Mexican Plateau
and in the Cordillera Volcánica, 15 have twelve longitudinal rows of
dorsal scales and 30 have fourteen rows. Of seven specimens from the
state of México, 5 have twelve rows and 2 have fourteen; of nine
specimens from central Veracruz, 8 have twelve rows and one has
fourteen; of six specimens from Hidalgo, 5 have twelve rows and one has
sixteen; of two specimens from Guanajuata, one has fourteen and the
other has sixteen rows. All of the 35 specimens from the Sierra de
Coalcomán have sixteen rows. Furthermore, these specimens have the
superciliary row extended anteriorly, so that the anterior superciliary
is in broad contact with the loreal. Specimens from Cerro Tancítaro have
a shorter superciliary row, so that the anterior superciliary is not in
broad contact with the loreal. These characters were used by Tihen
(1949:220) to distinguish Gerrhonotus imbricatus ciliaris from G.
imbricatus imbricatus. According to Tihen, the subspecies G.
imbricatus[Pg 88] ciliaris ranges from Guanajuato and Hidalgo northward to
Chihuahua and Coahuila, whereas the nominal subspecies occurs from
Michoacán and Hidalgo southward to Oaxaca. Specimens from the Sierra de
Autlán in Jalisco are like those from Cerro Tancítaro; consequently,
there seems to be no connection between the populations of G.
imbricatus ciliaris in the mountains of the northern part of the
Mexican Plateau with the ciliaris-like individuals found in the Sierra
de Coalcomán. The acquisition and study of additional material from
throughout the range of the species is necessary to clarify the picture
of geographic variation. Until then, I prefer to consider all of the
specimens from Michoacán as Gerrhonotus imbricatus imbricatus.

The largest specimen is a male having a snout-vent length of 136 mm. Two
juveniles collected in July 24, 1960, have snout-vent lengths of 36 and
42 mm. A specimen having a snout-vent length of 127 mm. and a tail
length of 145 mm. was regurgitated by a Crotalus pusillus, which had a
body length of 550 mm.

Gerrhonotus imbricatus imbricatus is an inhabitant of coniferous
forests. In the Cordillera Volcánica it occurs from 1500 to 3500 meters
at the top of Cerro Tancítaro. In the Sierra de Coalcomán it occurs from
2100 to 2700 meters. On July 4, 1955, a pair was found in copulation
beneath a pine log at 2700 meters on Cerro Barolosa. The male was lying
on top of the female and was holding her head firmly in his jaws; the
male’s tail was curled under the female’s tail, so that the cloacae were
in contact.

Serpentes

Typhlops braminus (Daudin)

Both specimens known from Michoacán were collected by Gadow in 1908.
Peters (1954:20) remarked that the specimen from Arteaga probably does
not indicate a rapid spreading of the species, which most likely was
introduced into México at the time that vessels were stopping at
Acapulco from the Philippines (Taylor, 1940b:444), but instead may
indicate that pack trains from Acapulco passed through the Sierra de
Coalcomán. The occurrence of this snake along a long-used camino
substantiates this belief.[Pg 89]

Leptotyphlops bressoni Taylor

This species still is known definitely only from the type specimen
collected on the lower slopes of the Cordillera Volcánica at the
northern edge of the Tepalcatepec Valley. A specimen (now lost) reported
from Aguililla by Cope (1887:63) possibly represents this species (see
Smith and Taylor, 1945:21, and Peters, 1954:20).

Leptotyphlops gadowi Duellman

No additional specimens of this species have been collected since the
species was described by Duellman (1956b:93). Data given with the
specimen by Gadow indicate that it came from his camp above Apatzingán
at an elevation of about 800 meters. Although the exact position of this
camp is unknown, the lower slopes of the Cordillera Volcánica above
Apatzingán usually support arid scrub forest at elevations below 1000
meters. Therefore, this species probably is an inhabitant of the arid
scrub forest.

Leptotyphlops phenops bakewelli Oliver

The five specimens from the coastal lowlands are from elevations of less
than 150 meters; these were collected by Peters (1954:20); the specimen
from La Salada is from an elevation of 580 meters in the Tepalcatepec
Valley. Peters (loc. cit.) remarked that the rostral and the tip of
the tail that were described as white by Oliver (1937:17) actually are
sulphur-yellow in life.

Loxocemus bicolor Cope

As noted by Peters (1954:21), this species was not recorded from
Michoacán by Smith and Taylor (1945:27), but Gadow (1930:30) collected a
specimen at La Orilla in 1908. This specimen (BMNH[Pg 90] 1914.1.28.124) is a
male having 235 ventrals and 47 caudals, a dark brown dorsum, and
cream-colored labials and venter. The anterior chin-shields are
considerably longer than the scales bordering the chin-shields. In these
characters this specimen agrees with the diagnosis of Loxocemus
bicolor given by Taylor (1940c:447), who revived Loxocemus
sumichrasti Bocourt. Of the six specimens from Apatzingán in the
Tepalcatepec Valley, three males have 243 to 253 (246.6) ventrals and 44
to 45 (44.3) caudals; three females have 238 to 247 (244.0) ventrals and
42 to 44 (43.0) caudals. Certain characters of scutellation utilized by
Taylor for separating L. bicolor and L. sumichrasti are inconsistent
in this series. The chin-shields are longer than the adjacent scales,
like those illustrated in L. bicolor by Taylor (op. cit., fig. 1).
The relative lengths of the prefrontal and internasal sutures are
subequal, or the prefrontal suture is slightly longer. Thus, in these
characters of scutellation these snakes are like L. bicolor, but in
coloration they are like L. sumichrasti; the dorsal color in life was
an iridescent dark bluish gray, and the belly was pale gray or bluish
gray.

The supposed differences in scutellation between L. bicolor and L.
sumichrasti have been questioned by Woodbury and Woodbury (1944:360);
these authors treated L. sumichrasti as a subspecies of L. bicolor.
As pointed out by Zweifel (1959b:5), such an arrangement is not tenable,
for, although individuals with each kind of color pattern have not been
collected together at any one locality, the over-all geographic picture
is one of sympatric distribution. Only snakes having the coloration of
L. sumichrasti have been collected in the Balsas-Tepalcatepec Basin. I
agree with Zweifel (loc. cit.) that on the basis of morphological
similarities and sympatric distribution, L. bicolor and L.
sumichrasti seem to be dimorphic phases of the same species, showing no
more striking differences in coloration than Lampropeltis getulus
californiae, a now classical example of pattern dimorphism in snakes.

In Michoacán, as in other parts of its range, Loxocemus bicolor
inhabits arid scrub forest environments at low elevations.

Boa constrictor imperator Daudin

These specimens have come from a variety of habitats from elevations of
less than 1,000 meters. The species seems to be equally[Pg 91] abundant in the
broad-leafed semi-deciduous forests of the coastal foothills and in the
arid Tepalcatepec Valley. In the latter area most of the specimens were
collected at night.

Coniophanes fissidens dispersus Smith

Further collecting in southern Michoacán has failed to add additional
material of this species, which is known in the state from the one
specimen collected by Gadow in 1908. The species possibly ranges
throughout the coastal foothills of the Sierra de Coalcomán. Peters
(1954:21) described the specimen from Arteaga.

Coniophanes lateritius lateritius Cope

The one specimen available from Michoacán of this apparently rare
species was discussed by Wellman (1959:127), who pointed out that
although the specimen was geographically intermediate between the
subspecies C. l. lateritius (Jalisco and Nayarit) and C. l.
melanocephalus (Morelos and Puebla), the specimen (UMMZ 118954) was
like C. l. lateritius in scutellation and in color pattern differed
from other known specimens of the species in having had in life a pale
orange, instead of a brick-red, dorsum. Additional specimens from the
Sierra de Coalcomán will be required in order to determine whether this
specimen is a representative of an orange-colored population or merely
is aberrant in coloration.

The present specimen is from an elevation of 900 meters in oak forest on
the southern slopes of the Sierra de Coalcomán; other locality records
for the species indicate that it inhabits broad-leafed forest in
foothills from Nayarit to Puebla.

Conophis vittatus vittatus Peters

All specimens of this terrestrial snake have been collected in areas of
scrub forest between 800 and 1100 meters above sea level. Since[Pg 92] the
species is known from the coastal regions of Guerrero and Colima, its
absence from the cost of Michoacán is unexplainable; probably the lack
of specimens from these areas is due solely to inadequate collecting.

Conopsis biserialis Taylor and Smith

This species is abundant in the coniferous forests at elevations from
1550 to 2800 meters throughout the Cordillera Volcánica; apparently it
does not occur in the Sierra de Coalcomán.

On August 1, 1956, a copulating pair was found beneath a rock at
Capácuaro.

One of the best characters to distinguish this species from Toluca
lineata, which occurs with Conopsis throughout its range in
Michoacán, is the presence of large, black ventral blotches in Conopsis
biserialis, as contrasted with the two rows of small black spots in
Toluca lineata.

Conopsis nasus Günther

This species has been collected in oak, pine-oak, and fir forests at
elevations of 1900 to 2450 meters on the mountains rising from the
Mexican Plateau. It does not seem to be so abundant as Conopsis
biserialis. Sufficient ecological data to determine differences in
habitat between the two species have not been compiled.

Diadophis dugesi Villada

Apparently this snake is uncommon in Michoacán. It has been found only
at elevations of 1900 to 2200 meters in pine and pine-oak forests on the
mountains rising from the Mexican Plateau.[Pg 93]

Dryadophis melanolomus stuarti Smith

The few specimens indicate that in Michoacán, as elsewhere on the
Pacific coast of México, this species is restricted to forested regions
on the coastal plain. It does not occur in the Tepalcatepec Valley.

The coloration, in life, of a juvenile (UMMZ 114604) is as follows: The
dorsum is uniform pale grayish tan on posterior one-third of body and on
tail; anteriorly there are pale grayish tan middorsal blotches separated
by grayish white interspaces, which are about one-half the length of the
blotches. Posteriorly the blotches are less distinct, fading into the
uniform grayish tan ground color of the posterior part of the body. The
blotches extend laterally onto the fourth and fifth scale rows. Large
squarish lateral intercalary blotches of darker brown interconnect with
the dorsal blotches. The top of the head is pale olive-brown; a dark
brown postorbital stripe extends from the eye to the posterior edge of
the last upper labial. The labials, chin, and ventrals 1-30 are creamy
white, changing to a dusty cream-color posteriorly; the chin and
ventrals 1-30 are heavily spotted with dark brown. The iris is a
cream-color above and chocolate brown below; the tongue is blue.

Drymarchon corais rubidus Smith

Not all of the specimens from Michoacán are typical in color pattern of
this subspecies, as defined by Smith (1941a:475). All specimens from the
Tepalcatepec Valley are uniformly black above; they have reddish or
cream-colored chins and the anterior two-thirds of the belly salmon-pink
or reddish buff. Individuals from the Sierra de Coalcomán (Arteaga and
Arroyo El Salto) are like those from the Tepalcatepec Valley. Three
specimens from the coastal lowlands differ noticeably in color pattern:

UMMZ 104504, adult male (Ostula).—Pale brown above flecked with black
anteriorly; at midbody, flecks form narrow transverse bands that become
progressively wider posteriorly, until on tail no brown pigment evident,
all ventrals reddish buff, except last eight, which are black.[Pg 94]

UMMZ 104602, adult female (La Placita).—Black above, reddish
cross-bands and flecks on all of body; dorsal and ventral surfaces of
tail black; chin cream-color and entire belly reddish buff.

UMMZ 114626, adult male (San Juan de Lima).—Black above; dull
rust-colored cross-bands on anterior half of body; chin white; belly
rust-colored on anterior two-thirds of body and black posteriorly.

One specimen from La Palma on the Mexican Plateau (KU 29275) has the top
of the head an olive-color, the entire dorsum black, the chin and
ventrals 1-42 a cream-color, remainder of venter black, and all of the
labials heavily barred with black. A juvenile from Capirio in the
Tepalcatepec Valley (UMMZ 114627) is black above and has pale
olive-colored flecks on the anterior one-third of the body; the top of
the head is dark olive-brown, and the sides of the head are somewhat
paler. Anteriorly the belly is a cream-color; posteriorly it is black.

The specimens from the Tepalcatepec Valley are typical of Drymarchon
corais rubidus. Those from the coastal lowlands differ in having large
areas of brown or red pigment on the dorsum, a condition not mentioned
by Smith in his description of the subspecies. The specimen from La
Palma, like many others from various localities on the Mexican Plateau,
resembles in certain characters D. corais orizabensis (Smith, op.
cit.: 477). Our knowledge of the geographical variation in coloration
in this species is incomplete; many populations have been assigned to
subspecific rank without justification.

In Michoacán this species is found from sea level to 1350 meters in the
Sierra de Coalcomán and to 1300 meters at La Palma on Lago de Chapala.
It has been collected in scrub forest, semi-deciduous broad-leafed
forest, and oak forest.

Drymobius margaritiferus fistulosus Smith

This snake is abundant in the lowlands of the state; the few specimens
listed above are indicative not of the rarity, but rather of the speed
and agility, of this diurnal snake. It most frequently is found near
water, where there is a dense growth of vegetation. One individual was
observed in a large pool inhabited by several small Rana pipiens, and
another was seen along the bank of a hyacinth-choked[Pg 95] river channel. A
third individual was captured while it was in pursuit of a
Cnemidophorus.

This species has been collected on the coastal lowlands and seaward
foothills of the Sierra de Coalcomán and in the Tepalcatepec Valley to
elevations of 1150 meters.

Elaphe triaspis intermedia (Boettger)

Dowling (1960) has shown that specimens from the Balsas-Tepalcatepec
Basin have fewer ventrals and caudals than those from the Sierra del Sur
or the coast. All specimens from Michoacán were collected in open
forest, either scrub or oak forest. They were found in drier situations
than those described for the species in southern Tamaulipas by Martin
(1958:69). In Michoacán Elaphe triaspis intermedia is known from the
Tepalcatepec Valley, the lower slopes of the Cordillera Volcánica, and
the western edge of the Mexican Plateau at an elevation of 1350 meters.
It probably occurs in the lower parts of the Sierra de Coalcomán and
along the Pacific coast, for it is known from the coastal lowlands of
Guerrero and Colima. In August, 1951, I saw a snake that probably was
this species in Barranca de Bejuco.

Enulius unicolor (Fischer)

This small snake has been collected from beneath rocks in brushy areas
and broad-leafed forest between 900 and 1800 meters; it has not been
found in coniferous forest. The limited ecological data suggest that the
species inhabits the transition zone between the tropical scrub forest
and the temperate hardwood forest.

All of the specimens have 17 rows of scales; four males have 169-178
(174.2) ventrals and 102-111 (106.8) caudals; two females have 192 and
195 ventrals and 96 and 87 caudals. Three individuals have one
postocular on one side and two on the other; in the other[Pg 96] specimens
there are two postoculars on each side. The largest male has a body
length of 232 mm. and a tail length of 130 mm.; the largest female has a
body length of 274 mm. and a tail length of 119 mm.

Geagras redimitus Cope

Previously this species was known definitely only from the Plains of
Tehuantepec, Oaxaca. Sphenocalamus lineolatus was described by Fischer
(1883:5) from Mazatlán; this name has been placed in the synonymy of
Geagras redimitus Cope. Although Fischer gave the type locality only
as “Mazatlán” and did not designate the state, it is probable that the
type originated from Mazatlán, Sinaloa. The present specimens are from a
locality almost midway between Tehuantepec and Mazatlán and support the
possibility that Geagras ranges along the Pacific coast of México from
Oaxaca to Sinaloa.

The two specimens from Michoacán (UMMZ 114446-7), both males, have 118
and 122 ventrals, 31 and 33 caudals, body lengths of 108 and 81 mm., and
tail lengths of 20 and 15 mm. Both have 1-1 preoculars, 1-1 postoculars,
1-2 temporals, 6-6 upper labials, and 5-5 lower labials. In life, the
dorsum was pale tan; the top of the head and the middorsal and lateral
stripes were dark brown; the belly was white. The occipital spots were
pale pinkish tan. Both specimens were found beneath rocks in tropical
semi-deciduous forest at an elevation of 15 meters on the coastal plain.

Geophis dugesi Bocourt

Aside from the three specimens listed above, there are two (SU 4407-8)
bearing the data “Michoacán.” Bocourt (1883:574) stated that the type
specimen from Tangancícuaro had six or seven pale cross-bands on the
anterior part of the body. An illustration, presumably of the same
specimen, by Dugès (1884:Pl. 9) shows five distinct and one indistinct
cross-bands. Of the four specimens that I have examined, none has more
than three pale cross-bands, and one has only one indistinct cross-band.
Two females have 154 and 158 ventrals and 38 and 37 caudals; two males
have 150 and 151 ventrals and 43 and 42 caudals.

This species is known only from elevations between 1750 and 2050[Pg 97] meters
on the southwestern edge of the Mexican Plateau in the state of
Michoacán.

Geophis incomptus Duellman

This species, which seems to be related to Geophis maculiferus, is
known only from the pine-oak forest in the vicinity of Dos Aguas
(elevation 2100 meters) in the Sierra de Coalcomán. Aside from the five
specimens comprising the type series, there are ten other specimens in
the Museum of Zoology at the University of Michigan collected by Floyd
L. Downs in July, 1960. Data from these specimens and those comprising
the type series show that in this sample seven males have 146-153
(149.3) ventrals and 35-37 (36.0) caudals; eight females have 150-154
(152.4) ventrals and 29-34 (32.5) caudals. The largest specimen is a
female with a body length of 344 mm. and a tail length of 53 mm.

Geophis maculiferus Taylor

The type and only known specimen of Geophis maculiferus (UIMNH 25078)
is a female having 140 ventrals and 30 caudals, dorsal scales in 15
rows, one postocular, and an anterior temporal. Only one other species
in México has dorsal scales in 15 rows and has an anterior temporal;
that species is G. incomptus, which differs from G. maculiferus in
having six or seven lower labials, instead of five, and in having the
edges of the ventrals dark, instead of a uniformly cream-colored belly.

The locality from which the specimen was obtained lies at an elevation
of 1630 meters on the southern slope of the Cordillera Volcánica. At
that elevation there is an interdigitation of arid tropical scrub forest
and pine-oak forest; probably Geophis maculiferus inhabits the
pine-oak forest.

Geophis nigrocinctus Duellman

The three specimens comprising the type series of the species were found
beneath logs and in a stump in pine-oak forest at an elevation of 2100
meters. A discussion of the variation in these[Pg 98] specimens and of
probable relationships of the species was given by Duellman (1959).
Floyd Downs spent several days at Dos Aguas in July, 1960; although he
found ten specimens of Geophis incomptus, no further specimens of G.
nigrocinctus were obtained.

Geophis petersi Boulenger

This seems to be the most widespread species of Geophis in Michoacán.
It has been found at elevations between 950 and 2350 meters, chiefly in
pine or pine-oak forest. Boulenger (1894:321) described Geophis
petersi from a specimen stated to be from Mexico City, a locality which
probably is in error. The only localities from which the species is
definitely known are those listed in this account.

Three males and five females from the Mexican Plateau and the Cordillera
Volcánica have respectively 140-144 (141.7) and 143-151 (146.0) ventrals
and 39-41 (40.0) and 29-35 (33.2) caudals. All have dorsal scales in 15
rows, 1 postocular, no anterior temporal, and a relatively small
triangular supraocular. The specimen from Coalcomán (UMMZ 104698) was
referred to Geophis nasalis by Peters (1954:22). This specimen is
abnormal in several characters; in five places there is a fusion and
separation of the vertebral and paravertebral scale rows, producing a
change from 17 to 15 rows of dorsal scales. Fusion of the three rows
takes place at the level of the 8th, 41st, 47th, 54th, and 65th
ventrals. Furthermore, there is a small secondary postocular on each
side of the head. In other characters the specimen is like G. petersi;
the resemblances to that species are greater than to G. nasalis, which
has been recorded from Guatemala and southern Chiapas.

Geophis tarascae Hartweg

A female of this species was collected in the Parque Nacional at the
north edge of Uruapan in 1899, and a male was taken there in 1947; these
specimens were used by Hartweg in his description of the species. Floyd
L. Downs obtained another specimen in the Parque Nacional on July 19,
1960. It has 164 ventrals and 46 caudals; in life, the ground color of
the neck was brown with a purplish tint; the dorsal markings were black;
the chin was a cream-color,[Pg 99] and the belly was white. This specimen is
distinguished from those of all other species of Geophis in Michoacán
in that it has dark irregular cross-bars on the dorsum and a row of dark
spots on the venter.

Hypsiglena torquata ochrorhyncha Cope

The systematic status of the geographic variants of Hypsiglena in
México and southwestern United States has been commented on by several
authors. Tanner (1944) considered H. torquata and H. ochrorhyncha to
be distinct species; Bogert and Oliver (1945:379) and Duellman
(1957b:238) presented evidence indicating that H. torquata and H.
ochrorhyncha intergrade in Sinaloa and southern Sonora. In Hypsiglena
the scutellation, including the numbers of labials, dorsals, ventrals,
and caudals, seem to vary in a clinal manner. Nevertheless, these snakes
can be divided into two distinct populations on the basis of the nuchal
color pattern, consisting of an ochrorhyncha-type (a broad dark
nape-band, the lateral edges of which extend anteriorly and fuse with a
postorbital stripe, and a narrow nape stripe extending from the
posteromedian edges of the parietals to the dark nape band) and a
torquata-type (a somewhat narrower dark nape-band bordered anteriorly
by a pale nuchal area, and no dark nape stripe). Snakes having the
ochrorhyncha-type of nuchal pattern are found on the Mexican Plateau
from Michoacán northward into the desert regions of Sonora and the
southwestern United States. Snakes having the torquata-type of pattern
are found on the coastal lowlands and adjacent slopes of the Sierra
Madre Occidental from southern Sinaloa to Colima and thence inland in
the Balsas-Tepalcatepec Basin to Morelos and Guerrero. An exception is
Hypsiglena torquata dunklei from Forlón and San Fernando, Tamaulipas;
it has the torquata-type of nuchal pattern. The distributional picture
is somewhat complicated because some individuals having the
torquata-type of nuchal pattern also have a faint nape stripe. If
these are taken as exceptions, the general picture of distribution in
México is H. t. torquata on the Pacific lowlands from Sinaloa
southward to the Balsas Basin and H. t. ochrorhyncha on the Mexican
Plateau.

Smith (1943:433) resurrected Hypsiglena jani Dugès for the snakes of
the ochrorhyncha-type on the southern part of the Mexican[Pg 100] Plateau. He
stated that the southern specimens differed from northern ones in having
a nuchal spot 9 or 10 scales in length, as compared with a spot 2 to 6
scales in length in northern specimens. A cursory examination of
specimens from the areas between Arizona and Michoacán showed that there
is a gradual increase in the size of the spot from north to south. If no
other characters can be found to distinguish the populations, they
should be considered as a single subspecies.

Hypsiglena affinis differs from H. torquata in possessing 19 instead
of 21 rows of dorsal scales. Additional material is needed from the
western slopes of Jalisco and the Barrancas in Zacatecas and Durango,
before definite allocation of affinis can be made.

Bogert and Oliver (1945:379) discussed the status of certain named
populations in Baja California and concluded that only one species
occurs there, and that the species probably is conspecific with H.
torquata. A careful review of the genus Hypsiglena might show that
there is only one species.

The one specimen from Michoacán (USNM 46513) is from an elevation of
about 2300 meters near the southern edge of the Mexican Plateau.

Hypsiglena torquata torquata (Günther)

Specimens from the three mentioned localities have the dark nuchal spot
bordered anteriorly by a pale blotch. In life the specimen from Capirio
(UMMZ 114424) had rich reddish brown dorsal spots; the dorsal ground
color was grayish white above and somewhat more gray laterally. The pale
nuchal area was a cream-color, and the iris was grayish red.

All of the specimens were found in the arid scrub forest in the
Tepalcatepec Valley at elevations between 200 and 350 meters.

Imantodes gemmistratus gracillimus (Günther)

The specimen from La Orilla was reported by Peters (1954:23) as
Imantodes gemmistratus oliveri; Zweifel (1959c) showed that I. g.
oliveri[Pg 101] did not range west of Tehuantepec and that the snakes
inhabiting the coastal lowlands of Guerrero, Michoacán, and Colima were
assignable to the subspecies gracillimus. It may be assumed that this
subspecies ranges throughout the coastal lowlands and foothills of the
Sierra de Coalcomán.

Imantodes gemmistratus latistratus (Cope)

The one specimen from Michoacán was collected near the upper limits of
the scrub forest on the slopes of the Cordillera Volcánica. Zweifel
(1959c:10) stated that in certain aspects of coloration this specimen
was like I. gemmistratus gracillimus, but in scutellation and other
features of coloration it was like I. g. latistratus. There are too
few specimens of this species to define the ranges of the various
subspecies with any degree of accuracy, but from the limited number of
specimens available, it seems that I. gemmistratus gracillimus occurs
on the Pacific lowlands from Guerrero northward to Colima. Northward on
the Pacific lowlands from Colima to Sinaloa and in the
Balsas-Tepalcatepec Basin is found I. gemmistratus latistratus.

Lampropeltis doliata (Linnaeus)

The few specimens of this species from Michoacán show a wide range of
variation; furthermore, the present systematic status of the subspecies
of Lampropeltis doliata portrays an incongruous pattern of
distribution. Specimens from the Sierra de Coalcomán have relatively
narrow red bands that are not interrupted dorsally by extensions of the
black rings; the scales in the red bands have black tips. The specimen
from El Sabino (EHT-HMS 5253) and the one from the Río Nexpa on the
coast (USNM 31491) have broader red bands; the scales in the red bands
do not have black tips. A specimen from 24 kilometers west of Morelia
(UIMNH 17782) and one from Uruapan (UMMZ 121508) have the red bands
interrupted dorsally by extensions from the black rings.

Specimens from the Sierra de Coalcomán were referred to L. doliata
blanchardi by Peters (1954:24), who noted that in some[Pg 102] characters
these snakes were like L. d. nelsoni and in others like L. d.
polyzona. The individual from El Sabino was referred to L. d. nelsoni
by Taylor (1940c:465); the one from 24 kilometers west of Morelia was
referred to L. d. arcifera by Smith (1942c:198). If these assignments
are correct, three subspecies of Lampropeltis doliata occur in
Michoacán: blanchardi in the Sierra de Coalcomán, nelsoni on the
coast and in the Tepalcatepec Valley, and arcifera on the Mexican
Plateau and in the Cordillera Volcánica. Such a distribution is
plausible, but the few specimens and our general lack of knowledge of
the variation and relationships of the different populations do not
permit a definite assignment at this time.

Lampropeltis ruthveni Blanchard

At the present time this species is known definitely from only three
localities on the Mexican Plateau in Michoacán. An incomplete skin from
El Sabino (EHT-HMS 5438) was referred to this species by Taylor
(1940c:465); the specimen cannot be found, so verification of the
identification cannot be made at this time.

Leptodeira latifasciata (Günther)

This nocturnal snake apparently ranges throughout the arid
Balsas-Tepalcatepec Valley to elevations of about 1050 meters. It has
been collected only in the arid scrub forest. Aside from the specimens
listed by Duellman (1958a:93), there is one (UMMZ 120223) having eight
body blotches, a body length of 510 mm. and a tail length of 103 mm.

Leptodeira maculata (Hallowell)

[Pg 103]

This snake is abundant in the arid Tepalcatepec Valley; most of the
specimens have been collected in arid scrub forest at elevations of less
than 500 meters. With the onset of the rains in late June and early
July, large numbers of these snakes can be found around temporary pools,
where they feed on small frogs and toads. In the dry season few
individuals were found, and all of those were beneath cover. Specimens
from the coast have more body-blotches than do those from the
Tepalcatepec Valley (Duellman, 1958a:56); otherwise the snakes show
little variation.

Leptodeira splendida bressoni Taylor

The range of Leptodeira splendida bressoni apparently does not overlap
that of Leptodeira maculata; the latter is restricted to the lower
reaches of the arid scrub forest, whereas L. s. bressoni inhabits the
upper limits of the arid scrub forest and the lower part of the pine-oak
forest. Specimens have been collected between 950 and 1630 meters on the
slopes of the Cordillera Volcánica and at 950 meters in the Sierra de
Coalcomán. At Uruapan individuals were found beneath rocks along a
stream and in a stone fence. Leptodeira duellmani, which was described
from Coalcomán by Peters (1954:25), is an aberrant individual of L. s.
bressoni (Duellman, 1958a:56).

Leptophis diplotropis (Günther)

Most specimens of this species have been collected in tropical
semi-deciduous forest at elevations of less than 1000 meters. In the
Sierra de Coalcomán one was taken in pine-oak forest at an elevation of
1700 meters near Ocorla; another was found in broad-leafed forest
between Aguililla and Dos Aguas at an elevation of 1600 meters. Most
individuals have been seen in trees or bushes. The absence of
broad-leafed forest in the Tepalcatepec Valley probably accounts for the
absence of this snake in that area.[Pg 104]

Manolepis putnami (Jan)

In Michoacán the species has been found only in tropical semi-deciduous
forest on the lower slopes of the Sierra de Coalcomán. From the
observations made by Peters (1954:28), this snake is diurnal and feeds
on teiid lizards.

Masticophis striolatus striolatus Mertens

This large diurnal species inhabits open scrub forest and cultivated
terrain from sea level to about 1650 meters. On the Mexican Plateau it
is known from the area around Lago de Chapala, to which it possibly
gained access through the valleys in the headwaters of the Tepalcatepec
drainage. Specimens from southern Michoacán have been reported
previously by Peters (1954:28) and Duellman (1954b:16) as Masticophis
flagellum lineatus.

Masticophis taeniatus australis Smith

This species reaches the southern limit of its distribution in the state
of Michoacán. The limited ecological data available suggest that the
species inhabits the open mesquite grassland of the Mexican Plateau.

Oxybelis aeneus auratus (Bell)

On the basis of the number of specimens seen and collected on the
seaward slopes of the Sierra de Coalcomán, this is a common snake[Pg 105]
there. Most specimens were collected in tropical semi-deciduous forest;
others were collected in oak forest to an elevation of 1700 meters.
Apparently Oxybelis does not inhabit the lower parts of the
Tepalcatepec Valley; the only specimens from the inland area are four
from El Sabino, which is situated at about 900 meters on the slopes of
the Cordillera Volcánica. One individual was seen in gallery forest near
Limoncito at an elevation of 730 meters on the northern slopes of the
Sierra de Coalcomán.

Pituophis deppei deppei (Duméril)

Duellman (1960b) showed that the widespread species Pituophis deppei
was composite and that the “lined subspecies” actually represented
another species, Pituophis lineaticollis. Pituophis deppei occurs
only on the Mexican Plateau; in Michoacán it inhabits mesquite grassland
and oak-bunch grass associations between 1900 and 2200 meters.

Pituophis lineaticollis lineaticollis (Cope)

This species reaches the northern limits of its range in the Sierra de
Coalcomán and on the Mexican Plateau in Michoacán. On the plateau it has
been collected in mesquite grassland at elevations between 1500 and 2000
meters. In the Sierra de Coalcomán individuals were found in open
pine-oak forest at 2100 meters elevation and in a meadow surrounded by
pine-oak forest at 2300 meters.

Pseudoficimia frontalis (Cope)

Most specimens were found beneath rocks in grassy areas near the upper
limits of the arid scrub forest, both in the Sierra de[Pg 106] Coalcomán and on
the southern slopes of the Cordillera Volcánica; all are from elevations
of less than 1100 meters. One specimen was found on a road at night near
Apatzingán. This species has been found in similar habitats near
Huajintlán, Guerrero, and in arid scrub forest at lower elevations in
Colima. It is unknown from the coast of Michoacán.

Pseudoficimia pulcherrima Taylor and Smith

This specimen (CNHM 39208) was reported by Schmidt and Shannon
(1947:81); they stated that it was a paratype of P. pulcherrima.
However, Taylor and Smith (1942a:246) did not mention the specimen;
aside from the type (EHT-HMS 5497), the only other specimen they
designated as belonging to the type series was UMMZ 85711 from
Chilpancingo, Guerrero.

The taxonomic validity of Pseudoficimia pulcherrima remains doubtful,
for only minor characters distinguish it from P. frontalis.
Furthermore, all known specimens of P. pulcherrima are from within the
geographic range of P. frontalis.

Rhadinaea hesperia hesperia Bailey

One specimen from Volcán Jorullo (UMMZ 104494), three from Arteaga (UMMZ
119281), and one from Uruapan (UMMZ 92342) are typical of the subspecies
R. h. hesperia in possessing a lateral cream-colored line on the sixth
and parts of the fifth and seventh dorsal scale rows and in lacking a
dark line on the second scale row. The specimens from El Sabino (EHT-HMS
5441 and UIMNH 18933) and one from Coalcomán (UMMZ 104502) have the
cream-colored line on the sixth and adjacent parts of the fifth and
seventh scale rows and have a dark line on the second scale row. Another
individual from Volcán Jorullo (UMMZ 104682) has cream-colored lines
like the others, but it possesses two lateral dark lines, one on the
second scale row, and one on the third.[Pg 107]

Smith (1942d:186) diagnosed Rhadinaea hesperia hesperioides as
differing from the nominal subspecies in having the cream-colored line
on the fourth and fifth scale rows and in possessing a dark line on the
second scale row. The specimens seen all have the lateral cream-colored
line centered on the sixth scale row, as is characteristic of R. h.
hesperia. Although many of the specimens also possess a dark line on
the second scale row, these specimens are here assigned to R. h.
hesperia. Additional specimens are necessary to define accurately the
subspecies and their ranges. Peters (1954:29) assigned the specimens
from Coalcomán to R. h. hesperioides.

In life the specimens from Arteaga had bright cream-colored temporal
stripes and dorsolateral stripes on the anterior part of the body. The
chin and anterior one-sixth of the belly was white; posteriorly the
venter was bright orange-red.

In Michoacán this snake has been found in tropical semi-deciduous
forest, arid scrub forest, and pine-oak forest at elevations from 850 to
1500 meters.

Rhadinaea laureata (Günther)

This snake is abundant in the Cordillera Volcánica, but it is unknown in
the mountains to the northeast of Morelia or in the Sierra de Coalcomán.
Most specimens were found beneath volcanic rocks imbedded in the ashy
soil in pine forest between 1800 and 2300 meters.

Rhadinaea taeniata (Peters)

This species, which is known only from a small region in the mountains
of Jalisco and central Michoacán, is represented by two specimens (CNHM
37130 and 39030) collected at Tancítaro (see Schmidt and Shannon,
1947:80).[Pg 108]

Salvadora bairdi Jan

This species is abundant on the Mexican plateau, where it inhabits the
more grassy areas in the mesquite grassland and cutover land in the pine
forests from 1550 to 2500 meters. Davis and Dixon (1957:21) described a
specimen from Zacapu as having two dark paravertebral stripes diverging
on the temporals and extending through the eye onto the loreal, a
characteristic of Salvadora lineata. On the basis of this specimen,
Davis and Dixon suggested that Salvadora bairdi and S. lineata were
subspecifically related. The examination of the large number of
specimens from Michoacán has revealed this kind of coloration in only
one other specimen, an individual from Tacícuaro, in which the stripes
diverge, but do not extend through the eye onto the loreal. Data on
scutellation for the large series from Tancítaro were given by Schmidt
and Shannon (1947:78), and for the series from Tacícuaro by Smith
(1943:466).

Salvadora mexicana (Duméril, Bibron, and Duméril)

This is one of the most abundant snakes in the arid lowlands of the
Tepalcatepec Valley; observations indicate that it probably is equally
abundant on the coastal lowlands. Near Apatzingán as many as five of
these snakes have been seen in one-half hour. The snakes seem to be
equally abundant and active in the dry season and in the rainy season.
Most individuals were seen on the ground, but two were found in low
trees. On several occasions Salvadora mexicana was observed in pursuit
of lizards on the ground. Captured individuals regurgitated
Cnemidophorus costatus zweifeli, Cnemidophorus deppei infernalis,
Sceloporus horridus oligoporus, Sceloporus pyrocephalus, and
Urosaurus gadowi.

Salvadora mexicana inhabits only the arid scrub forest at elevations
from sea level to about 1000 meters.[Pg 109]

Sibon nebulatus (Linnaeus)

The one specimen from Michoacán was collected by Peters (1954:30) in
tropical semi-deciduous forest on the coastal foothills of the Sierra de
Coalcomán. As presently known, the range of this species in western
México extends from Chiapas to Nayarit. Throughout this region the
species avoids scrub forest; this may explain its absence in the
Balsas-Tepalcatepec Valley.

Sonora michoacanensis michoacanensis (Dugès)

These specimens, together with all known specimens from the Sierra del
Sur in Guerrero (KU 23790-1, MVZ 45123) and the upper Balsas Basin in
Puebla (UIMNH 41688), are referable to S. m. michoacanensis. The
dorsal pattern consists of a highly variable number of cross-bands of
red, white, and black. In the specimens from Michoacán there are as many
as 17 red cross-bands on the body. One specimen from Apatzingán (CNHM
37141) has just behind the head a white band, bordered on either side by
a narrow black band; posteriorly the body is uniform red. Two specimens
from Coalcomán (UMMZ 109905-6) have respectively 11 and 13 red
cross-bands and 20 and 17 white cross-bands, and the posterior part of
the body is devoid of red color. Other specimens from these localities
have red, black, and white cross-bands throughout the length of the
body.

Sonora michoacanensis michoacanensis is distinguished from S.
michoacanensis mutabilis by the presence of cross-bands on the tail in
the latter (Stickel, 1943:116). One specimen from Coalcomán (UMMZ
109904) has one narrow band on the tail; all others from Michoacán have
uniformly red tails.

Apparently Sonora michoacanensis michoacanensis ranges in semi-arid
and arid habitats from the upper Balsas Basin in Puebla westward to the
lower slopes of the Sierra de Coalcomán, whereas S. m.[Pg 110] mutabilis
lives in foothills of the Sierra Madre Occidental from southern Jalisco
to Nayarit. Zweifel (1959b:6) presented evidence to show that specimens
of S. m. mutabilis supposedly from “Distrito Federal” probably bear
erroneous locality data.

Tantilla bocourti (Günther)

This small snake is an inhabitant of the coniferous forests and the
pine-oak forests on the Cordillera Volcánica. Data on the series from
between Zitácuaro and the Río Tuxpan were given by Taylor (1940c:481).

Tantilla calamarina Cope

Although this snake has been collected at high elevations along the rim
of the Mexican Plateau in Nayarit, Jalisco, México, and Puebla, the
specimens from Michoacán are from arid scrub forest at elevations of
less than 400 meters. The species has been found in similar habitats in
Colima (Oliver, 1937:24) and in Sinaloa and the Tres Marías Islands
(Zweifel, 1960:110).

Toluca lineata lineata Kennicott

This small snake is an inhabitant of the coniferous forests between
elevations of about 1550 and 2800 meters. Not infrequently, individuals
have been found in pine-oak forest within these elevations.

The generic status of Toluca is unsettled. Taylor and Smith (1942b)
separated Toluca from Conopsis by the presence of enlarged and
grooved posterior maxillary teeth in Toluca and their absence in
Conopsis. Bogert and Oliver (1945:378) suggested synonymizing Toluca
with Conopsis. Smith and Laufe (1945:12) defined the generic position
of Toluca. Actually, in deciding the generic position of these snakes,
five genera (Ficimia, Gyalopion, Pseudoficimia, Conopsis, and
Toluca) must be considered. Of these[Pg 111] Ficimia and Gyalopion are
closely related; they have been placed in one genus by some workers.
Pseudoficimia is intermediate between Ficimia-Gyalopion and
Toluca-Conopsis. A workable definition of the supraspecific
classification of these snakes must await a thorough review of the
species.

Trimorphodon biscutatus biscutatus (Duméril, Bibron, and Duméril)

In the arid lowlands of the Tepalcatepec Valley and presumably also in
the scrub forest of the coastal lowlands, this is an abundant snake,
which is active only at night. Usually snakes of this species are found
on the ground, but one large individual was observed at night in a low
tree. That individual defied capture by widely opening its mouth and
striking repeatedly at the collector. The excreta of one specimen
contained feathers of an unidentified species of bird.

Trimorphodon latifascia Peters

In Michoacán this species has been collected in semi-arid habitats at
elevations from 300 to 1430 meters in the Tepalcatepec Valley and lower
slopes of the Cordillera Volcánica. In this area it occurs sympatrically
with Trimorphodon biscutatus biscutatus.

In life, adults have a pale tan dorsal ground color and rich chocolate
brown cross-bands; the eye is pale grayish tan. A juvenile from
Coalcomán has black cross-bands on a pale grayish tan ground color. As
stated by Schmidt and Shannon (1947:83) and Peters (1954:32), the type
specimen of Trimorphodon fasciolata Smith from Cascada Tzararacua is
indistinguishable from specimens of Trimorphodon latifascia.

Seven males have 209 to 223 (216.5) ventrals; one female has 227
ventrals. The number of dark cross-bands on the body varies from 12 to
16 (13.5). The relationships of this species are with[Pg 112] Trimorphodon
tau on the Mexican Plateau. In fact, additional specimens from the
headwaters of the Tepalcatepec Valley and the lower slopes of the
Mexican Plateau in eastern Michoacán and adjacent Jalisco may show that
the two are conspecific. Trimorphodon latifascia differs from tau in
having fewer dark cross-bands on the body and in lacking an interocular
bar.

Trimorphodon tau Cope

Two of the specimens from Michoacán (UMMZ 118948 from Tangamandapio and
UIMNH 19138 from Tacícuaro) have cream-colored, Y-shaped marks on the
head. These markings supposedly are characteristic of Trimorphodon
upsilon. One specimen from Emiliano Zapata (UMMZ 118950) and one from
between Morelia and Ciudad Hidalgo (EHT-HMS 21402) have a cream-colored
line on the parietal suture; in another specimen from Emiliano Zapata
(UMMZ 118949) the anterior end of this line is expanded, giving the
appearance of an incipient “Y”. Thus, the nature of the markings on the
head in specimens from Michoacán is intermediate between the typical
condition in Trimorphodon tau and the usual condition in T. upsilon.
Smith and Taylor (1945:148) gave the range of Trimorphodon tau as:
“Central Guerrero, in the Sierra Madre del Sur; central Oaxaca; and the
edge of the plateau in central Michoacán.” They gave the range of
Trimorphodon upsilon as: “Southern Chihuahua south to central
Michoacán, east to central Hidalgo.” Specimens referable to T. tau
have been found at La Joya de Salas, near Ciudad Victoria, and near
Llera, Tamaulipas (see Smith and Darling, 1952:85, and Martin, 1958:74).
Some of these specimens also show combinations of characteristics of T.
tau and T. upsilon. Smith and Darling (loc. cit.) suggested that
T. tau and T. upsilon be considered as subspecies. However, if T.
tau and T. upsilon are subspecies, intergrades would be expected
between the ranges of the two populations and not on the northeastern
and southwestern periphery of their combined ranges. Instead, the
limited evidence now available suggests that T. tau and T. upsilon
are names based on a highly variable character of color pattern of the
head, and that only one species is involved.

In Michoacán this species inhabits the mesquite grassland on the Mexican
Plateau.[Pg 113]

Tropidodipsas occidentala Oliver

This specimen was reported by Peters (1954:34), who found it beneath a
rock at the mouth of a heavily wooded ravine near Coalcomán at an
elevation of 950 meters. The only other known specimen is from Comala,
Colima, a village, like Coalcomán, that is located near the upper limits
of the arid scrub forest.

Natrix valida isabelleae Conant

Three females and one male have, respectively, 133, 135, 135, and 131
ventrals, and 68, 68, 73, and 75 caudals. The grayish stippling on the
posterior ventral surfaces mentioned by Conant (1953:9) is not visible
on these specimens. In the small individuals from Punto San Juan de Lima
and from Coahuayana there are four longitudinal rows of dark spots on
the dorsum; in two large females from Playa Azul the spots are barely
discernible.

All of the specimens from Michoacán were found in the coastal lowlands;
those from Playa Azul were collected from a small brackish,
mangrove-lined lagoon.

Storeria storerioides (Cope)

Three males and six females from the Sierra de Coalcomán have,
respectively, 122-128 (125.3) and 126-136 (130.0) ventrals, and 46-47
(46.7) and 38-42 (39.1) caudals. Four males and eleven females from the
Cordillera Volcánica have, respectively, 124-132 (128.5) and 127-139
(136.4) ventrals, and 43-48 (44.7) and 38-44 (40.2) caudals. These data
show that, although there is little difference in the number of caudals,
specimens from the Sierra de Coalcomán have fewer ventrals than do
specimens from the Cordillera Volcánica. Of eleven specimens from the
Sierra de Coalcomán, two have black bellies. Five others from the Sierra
de Coalcomán and one from Puerto de Garnica in the Cordillera Volcánica
have[Pg 114] the bellies heavily stippled with black, giving a gray appearance.
Melanistic tendencies in this species have been discussed by Anderson
(1960:64), who examined the specimen from Tzitzio. In life, one specimen
from Dos Aguas (UMMZ 119451) had a cream-colored belly; the edges of the
ventrals were dark brick-red.

In Michoacán this snake inhabits pine-oak, pine, and fir forests at
elevations between 1550 and 2800 meters in the Cordillera Volcánica and
the Sierra de Coalcomán. Most specimens were found beneath rocks; the
one from Tzitzio was removed from the stomach of a Mexican Motmot
(Anderson, 1960:66).

Thamnophis dorsalis cyclides Cope

The snakes comprising the former Thamnophis eques-group have undergone
extensive taxonomic and nomenclatural shuffling by Smith (1942 and
1951), Bogert and Oliver (1945), Milstead (1953), and Fitch and Milstead
(1961). Smith recognized in Michoacán three members of the T. eques (=
dorsalis) complex: eques eques, eques postremus, and vicinus.
Later, Smith (1951) showed that the specific name eques had been
misapplied, so that T. eques eques became T. cyrtopsis cyclides, and
T. eques postremus became T. cyrtopsis postremus; under this
arrangement T. vicinus stood unchanged. In the meantime, Bogert and
Oliver (1945:359) presented a reinterpretation of Smith’s data and
suggested that T. vicinus, which differs from T. dorsalis cyclides
only in lacking a middorsal stripe, “… is not a species, but only a
pattern phase, possibly a simple mutant of T. e. eques” (= T.
dorsalis cyclides, by present arrangement). Milstead (1953) agreed with
Bogert and Oliver on the status of T. vicinus; furthermore, on the
basis of only a few specimens, Milstead concluded[Pg 115] that T. cyrtopsis
postremus was not subspecifically distinct from T. cyrtopsis
cyclides. Recently, Fitch and Milstead (1961) showed that Thamnophis
dorsalis Baird and Girard (1853) was the correct name for the snakes
that had been recognized as Thamnophis cyrtopsis Kennicott (1860).
Consequently, the snakes referred to T. eques eques by Smith (1942)
and to T. cyrtopsis cyclides by Smith (1951) and Milstead (1953) are
now T. dorsalis cyclides.

Aside from one specimen from Temazcal and nine from Morelia (paratypes
of T. vicinus), only two other specimens completely lacking the
middorsal stripe have been seen; one is a male (UMMZ 102510) having 161
ventrals and an incomplete tail from Pino Gordo, and the other is a male
(CNHM 39060) from Tancítaro having 158 ventrals and an incomplete tail.
A female from Tancítaro (CNHM 39061) having 153 ventrals and 77 caudals
has no lateral stripes and only a narrow middorsal stripe on the
anterior part of the body. Throughout the region where T. vicinus-like
snakes have been found, typical T. dorsalis cyclides occurs in much
greater numbers. I concur with Bogert and Oliver in placing T. vicinus
as a synonym of T. dorsalis cyclides.

Fig. 10. Dorsal color pattern of Thamnophis dorsalis
cyclides (A) and Thamnophis dorsalis postremus (B).

Milstead (1953) had available few specimens of Thamnophis dorsalis
from the Tepalcatepec Valley. The large series now in existence shows
that the population in the Tepalcatepec Valley differs distinctly from
that inhabiting the Mexican Plateau, Cordillera Volcánica, and Sierra de
Coalcomán. Therefore the name T. dorsalis postremus Smith (1942) is
resurrected for the population[Pg 116] in the Tepalcatepec Valley. T. dorsalis
cyclides and T. dorsalis postremus differ in color pattern (Fig. 10)
and in scutellation (Table 6). Specimens from the Mexican Plateau and
mountain ranges have a distinct light stripe on the second and third
scale rows, a dark brown dorsum having squarish black spots, and a row
of dark spots on the first row of dorsal scales. Specimens from the
Tepalcatepec Valley have a grayish brown dorsum having smaller and less
distinct dark spots and no light stripe on the second and third scale
rows; the first, second, and third rows of scales are colored like the
venter. In some specimens there are small dark flecks on the first row
of dorsal scales.

Table 6.—Variation in Scutellation in Thamnophis dorsalis.

One specimen from Uruapan (1550 meters) and one from Coalcomán (950
meters) are intermediate in color pattern between T. dorsalis cyclides
and T. dorsalis postremus. Both have indistinct lateral stripes and
only small dark spots below the stripes. In scutellation these specimens
are like T. dorsalis cyclides.

In Michoacán Thamnophis dorsalis cyclides has been collected in a
variety of habitats on the Mexican Plateau: pine-oak forest, fir forest,
marshes, and cleared land from 1550 to 2800 meters. In the Sierra de
Coalcomán one was taken in broad-leafed forest at 950 meters, three in
pine-oak forest at 2100 meters, and one in pine forest at 2300 meters.[Pg 117]

Thamnophis dorsalis postremus Smith

The reasons for recognizing the population of Thamnophis dorsalis in
the Tepalcatepec Valley as distinct from that on the surrounding
highlands are presented in the discussion of Thamnophis dorsalis
cyclides. In certain features of coloration and in the low numbers of
ventrals and caudals, T. dorsalis postremus shows more resemblance to
T. dorsalis sumichrasti than to T. dorsalis cyclides. According to
Milstead (1953:367), T. dorsalis cyclides ranges southward from the
Río Balsas in southwestern México. If specimens could be obtained from
the upper Balsas Basin they might show that T. dorsalis postremus
inhabits that extensive basin.

In the Tepalcatepec Valley T. dorsalis postremus is most frequently
found at night in the rainy season, at which time the snakes are
abundant near temporary pools where frogs are breeding. The absence of
specimens from the coastal lowlands of Guerrero, Michoacán, and Colima
indicate that, although the species inhabits the lowlands of the
Tepalcatepec Valley, its range does not include the coastal lowlands.

A female (UMMZ 119402 from Cuatro Caminos) having 139 ventrals and a
body length of 576 mm., on June 20, 1958, gave birth to 25 young, of
which 18 (9 males and 9 females) were preserved. In body length the
males varied from 132 to 141 (137.3) mm.; the females, 125 to 137
(133.1) mm. In tail length the males varied from 38 to 44 (42.4) mm.;
females, 35 to 42 (39.7) mm. The males have 138 to 147 (142.2) ventrals
and 70 to 75 (72.9) caudals; females have 131 to 140 (135.8) ventrals
and 63 to 71 (67.0) caudals.

Thamnophis eques eques (Reuss)

[Pg 118]

Although this snake has been collected in open pine-oak forest and in
oak-bunch grass associations, it seems to reach its greatest abundance
in marshes on the Mexican Plateau at elevations of 1550 to 2300 meters.

Thamnophis melanogaster canescens Smith

This species of garter snake seems to be most abundant in the marshes
adjacent to the lakes on the Mexican Plateau in Michoacán and Jalisco.
At these elevations (1550 to 2200 meters) it often is found in
association with Thamnophis eques eques and sometimes with Thamnophis
dorsalis cyclides. On June 11, 1958, individuals of this species were
found in a hyacinth-choked marsh at Tangamandapio at night.

One specimen from Tangamandapio (UMMZ 119414) had, in life, a dark
chocolate brown dorsum, reddish brown sides, and cream-colored belly,
chin, and labials. There were no longitudinal dorsal stripes.

Thamnophis scalaris scaliger (Jan)

The few specimens of this species from Michoacán have been collected at
elevations from 1800 to 3400 meters in pine or fir forest in the
Cordillera Volcánica.

Micrurus distans michoacanensis (Dugès)

All specimens were collected in the arid scrub forest of the
Tepalcatepec Valley. The number of black rings on the body varies from
six to eleven. In this respect they agree with the diagnosis of this
subspecies presented by Zweifel (1959b:9).[Pg 119]

Micrurus laticollaris (Peters)

This species ranges throughout the Balsas-Tepalcatepec Basin westward
into Colima; specimens from Michoacán were collected in arid scrub
forest at elevations from 500 to 1050 meters. The limited observations
on Micrurus distans michoacanensis and M. laticollaris indicate
that, at least in the Tepalcatepec Valley, M. laticollaris seems to
inhabit slightly more mesic areas than does M. distans michoacanensis.

Pelamis platurus (Linnaeus)

In November, 1955, Alfonzo Gonzales, a geographer from the University of
Texas, observed sea snakes on the beaches of Michoacán. In May, 1956,
Donald D. Brand of the University of Texas gave me one specimen of
Pelamis platurus that he obtained on March 2, 1956, at Boca de Apiza.
Furthermore, he supplied me with the following observations based on his
field work along the coast of Michoacán from the Río Coahuayana to
Maruata from March 1, to April 15, 1956. At that time many sea snakes
were observed; in some places living and dead individuals were seen on
the beaches; innumerable snakes were seen in the surf. When live
individuals were taken from the beach and thrown into the ocean, they
usually swam to shore. Many partially eaten individuals were seen
protruding from crab holes. Inquiries among the natives resulted in the
following information: Sea snakes are frequently seen between November
and April, but most commonly in March and April, at which time the water
is cold. The natives referred to the sea snakes as “culebra del mar.”
Most natives said that the snakes were not poisonous; others did not
know of any venomous properties. In May, 1956, I worked the coastal
region from the Río Coahuayana to La Placita and saw no sea snakes. In
the summer of 1950 James A. Peters, and in the summer of 1951 I worked
nearly the entire coastal region of Michoacán; during[Pg 120] that time no
Pelamis were seen. Insofar as I know, this is the first report of such
seasonal activity in Pelamis platurus in the Americas.

Agkistrodon bilineatus bilineatus Günther

All specimens from Michoacán are from inland localities between 300 and
1500 meters. The one from Los Reyes (USNM 46416) was collected by Nelson
and Goldman on February 13, 1903. The elevation of Los Reyes (1500
meters) seems unusually high for this species, but otherwise there is no
reason to doubt the authenticity of the record. Goldman (1951:192) in
his description of Los Reyes stated: “Los Reyes is near the boundary
between the Lower Austral and Arid Upper Tropical Zones but is
preponderantly tropical in zonal character. The regular crops are mainly
sugar cane, rice, and corn.” Thus the biotic features of the area are
not noticeably different from those at El Sabino and La Playa at lower
elevations. The development of extensive agriculture through irrigation
in the Tepalcatepec Valley and planting of rice and sugar-cane in that
area may produce a more widespread habitat for this snake.

The absence of specimens from the coastal lowlands is due solely to
inadequate collecting; the natives there know the snake and report that
it is not uncommon in certain areas.

Crotalus basiliscus basiliscus (Cope)

Specimens from southern Michoacán have fewer ventrals and caudals than
do those from the northern part of the range; three males and three
females have, respectively, 178, 182, 182, 185, 186, and 188 ventrals,
and 27, 28, 29, 22, 29, and 29 caudals. Klauber (1952:81) gave the
following data for Crotalus basiliscus (based on specimens from the
entire range, except Oaxaca): ventrals in males, 179-201 (191.4), in
females, 185-206 (197.6); caudals in males, 26-36 (30.7), in females,
21-29 (24.4). Klauber (1952:84) remarked that the one specimen that he
had seen from Apatzingán[Pg 121] had fewer ventrals and caudals than most other
specimens. The low numbers of ventrals and caudals in specimens from
Michoacán, as compared with more northern populations, may be indicative
of a trend in the reduction of the numbers of these scutes from north to
south. The southernmost examples of Crotalus basiliscus (Crotalus
basiliscus oaxacus from Oaxaca) have 172-175 ventrals and 21 caudals
(Gloyd, 1948).

In Michoacán Crotalus basiliscus basiliscus has been found in arid
habitats on the coast, in the Tepalcatepec Valley, and in the lower
parts of the Sierra de Coalcomán. All specimens are from localities
below 1070 meters in elevation.

Crotalus durissus culminatus Klauber

These specimens are part of the type series and were collected by Hobart
M. Smith near the upper limits of the arid scrub forest at an elevation
of about 1050 meters on the lower slopes of the Cordillera Volcánica at
the northern edge of the Tepalcatepec Valley. They were discussed in
detail by Klauber (1952:66-70).

Crotalus intermedius intermedius Troschel

The one specimen is from the pine forests on the Cordillera Volcánica.
At the present time this species is known from scattered localities in
west-central Veracruz, Oaxaca, Michoacán, and as Crotalus intermedius
omiltemanus in Central Guerrero. Apparently it is restricted to montane
environments.

Crotalus molossus nigrescens Gloyd

In Michoacán this species has been found in pine forests between 1550
and 2300 meters in the Cordillera Volcánica. I expected to find it in
the Sierra de Coalcomán, but inquiries among the natives living in the
pine forests of that mountain range revealed that the people there have
no knowledge of a large species of rattlesnake.[Pg 122]

Crotalus polystictus (Cope)

Formerly this species was abundant in the marshes around Lago de
Chapala. The draining of these marshes probably resulted in reducing the
numbers of these rattlesnakes. The species is known only from the
Mexican Plateau at elevations of 1450 to 2400 meters.

Crotalus pusillus Klauber

Aside from the type series of Crotalus pusillus from Cerro Tancítaro
and one specimen from Carapan referred to the species by Klauber
(1952:38), there are fourteen specimens from the Sierra de Coalcomán.
These specimens (UMMZ 112566-7, 118591-9, 118601, 121512-3) are like
Crotalus pusillus from Cerro Tancítaro in having the prefrontals
paired, a black proximal rattle, and the underside of the tail black.
The prefrontals are bordered posteriorly by one scale in two specimens,
by two scales in three specimens, and by three scales in the other nine.
The snakes from the Sierra de Coalcomán have 40 to 46 (42) dorsal body
blotches. Ten males have 150-158 (154.4) ventrals and 29-33 (31.0)
caudals; two females have 157 and 160 ventrals, and 25 and 27 caudals.
The largest specimen is a male having a body length of 545 mm. and a
tail length of 63 mm. The only noticeable difference between the
specimens from the Sierra de Coalcomán and the topotypic series is that
the latter have fewer dorsal blotches; the range of variation is 33 to
46 (39.8).

Most specimens of this species have a grayish brown dorsum and dark
brown dorsal blotches. Two specimens from Dos Aguas (UMMZ 118596 and
118599) are pale brown above and have indistinct blotches.

One specimen from Dos Aguas regurgitated a large Gerrhonotus imbricatus
imbricatus; of two others from the same locality, one regurgitated a
Sceloporus bulleri and an Eptesicus fuscus. The latter specimen was
collected at the entrance of a small cave, where it probably had
captured the bat.

In the Cordillera Volcánica Crotalus pusillus has been obtained[Pg 123] in
pine-oak forest at elevations between 1550 and 1800 meters. In the
Sierra de Coalcomán two specimens were taken in pine forest at an
elevation of 2300 meters; ten other were found beneath rocks and logs in
pine-oak forest at an elevation of 2100 meters.

Crotalus triseriatus aquilus Klauber

I am following Klauber (1952) in assigning some of the specimens of this
species from Michoacán to the subspecies aquilus and others to C. t.
triseriatus. The distinguishing characters of these subspecies are
given by Klauber (1952:28). On the basis of the few localities from
which the species is known in Michoacán it seems as though C. t.
aquilus inhabits the open grassy areas on the Mexican Plateau and the
associated open pine-oak or oak-bunch grass habitats to the north and
east of the Cordillera Volcánica. Crotalus triseriatus aquilus has
been collected at elevations from 1600 to 2000 meters in Michoacán.

Crotalus triseriatus triseriatus (Wagler)

This small rattlesnake inhabits rocky areas in pine and pine-oak forests
above 1600 meters in the Cordillera Volcánica; it has been collected at
3270 meters on Cerro Tancítaro. The series reported by Schmidt and
Shannon (1947:84) is a mixture of specimens of Crotalus triseriatus
and Crotalus pusillus. The two species are found together on Cerro
Tancítaro, but only Crotalus pusillus inhabits the coniferous forests
of the Sierra de Coalcomán. Klauber (1952:30) stated that despite the
proximity of Crotalus triseriatus triseriatus and Crotalus
triseriatus aquilus in Michoacán, there is no evidence of
intergradation. He went on to suggest that additional material might
show that the two named populations actually are distinct species. The
specimens that have been studied since Klauber’s investigations also
show no evidence of intergradation, but there still is no known sympatry
of the populations.

The small montane rattlesnakes belonging to the species C. pricei, C.
pusillus, and C. triseriatus present a problem in systematics and
distribution worthy of intensive investigation. A knowledge of the[Pg 124]
distribution and relationships of the various populations of these
snakes, together with other species also living in isolated populations
on the higher mountains in México, probably will be of great
significance in understanding dispersal and differentiation of animals
during the Pleistocene.

SPECIES OF QUESTIONABLE OCCURRENCE

Some species for which there are no authentic records from Michoacán can
be expected there on zoogeographic probability. Other species have been
recorded from Michoacán, but these records are doubtful for any one of
several reasons. Fifteen species of such questionable occurrence are
discussed below:

Syrrhophus modestus modestus Taylor

This small terrestrial frog is not uncommon on the coastal lowlands and
foothills in Nayarit and in Colima, where it has been collected within a
few kilometers of the Michoacán border. At Tecolapa, Colima, on August
9, 1956, Syrrhophus modestus modestus was found with Tomodactylus
nitidus orarius, Bufo marinus, Bufo marmoreus, Hyla baudini,
Hyla smithi, and Phyllomedusa dacnicolor, all of which occur on the
coastal lowlands of Michoacán. Because of its solitary and secretive
habits, Syrrhophus modestus modestus is not common in collections.
Additional field work on the coast of Michoacán should reveal the
presence of the species there.

Hyla microcephala sartori Smith

On August 28, 1960, J. R. Dixon obtained a series of this species from a
temporary pond 6 kilometers northeast of La Resolana, Jalisco.
Previously, Hyla microcephala sartori had been known only from the
lowlands of Guerrero and Oaxaca. The existence of the species in Jalisco
provides evidence that this frog also occurs in Michoacán and Colima.

Gastrophryne usta usta (Cope)

Smith and Taylor (1948:93-4) listed specimens of this species from
Organos and El Treinta, Guerrero, and from Paso del Río,[Pg 125] Quesería,
Santiago, and Tecomán, Colima. The species occurs from Sinaloa and
central Veracruz southward at low elevations to the Isthmus of
Tehuantepec and thence along the Pacific lowlands into Central America.
Almost certainly it occurs on the coastal lowlands in Michoacán. Since
the amphibian fauna of the Tepalcatepec Valley has been better sampled
than that of the coast, I suspect that if Gastrophryne occurred in the
Tepalcatepec Valley, I would have found it there.

Lepidochelys olivacea (Eschscholtz)

According to Smith and Taylor (1950b: 15), this sea turtle is known from
the entire Pacific coast of México; these authors reported the species
from Chiapas, Oaxaca, Guerrero, Colima, and Sonora. Although the only
sea turtle that I observed in Michoacán is Chelonia mydas, others
probably do use the sheltered beaches for nesting. The scanty records of
sea turtles along the Pacific coast of México indicate that Chelonia
mydas and Lepidochelys olivacea are the most abundant species in that
region. There are scattered records of Dermochelys coriacea, Caretta
caretta, and Eretmochelys imbricata along the Pacific coast. The
occurrence of any of these along the coast of Michoacán is probable.

Geoemyda pulcherrima pulcherrima (Gray)

Smith and Taylor (1950b:30) recorded this species from Sonora, Sinaloa,
Nayarit, Colima, and Guerrero; these records indicate that the species
probably is distributed along the Pacific coast of México southward from
southern Sonora. It unquestionably occurs on the coast of Michoacán.
Natives of the coastal lowlands tell of another “tortuga de la tierra”
besides Geoemyda rubida. In the collections of the Museum of Natural
History of the University of Illinois is a specimen of Geoemyda
pulcherrima from Mexcala in the Balsas Basin in northern Guerrero. On
the basis of this specimen it is highly probable that the species also
inhabits the Balsas-Tepalcatepec Basin in Michoacán.[Pg 126]

Pseudemys scripta ornata (Gray)

The systematics and distribution of Pseudemys scripta in México and
Central America are poorly understood. Smith and Taylor (1950b:32)
recorded this turtle from the Pacific lowlands of Sinaloa, Jalisco,
Oaxaca, and Chiapas. This species is represented by vicarious
populations throughout the Atlantic lowlands of México, northwestern
México, over much of the United States, and also in Baja California.
Along the Pacific coast of México the species seems to be extremely
rare, or, at least, only locally abundant. Since the species has such a
wide distribution, and since it occurs on the Pacific lowlands both to
the north and to the south of Michoacán, it is reasonable to expect its
presence on the coast of Michoacán. Inquiries among the natives living
in the Balsas-Tepalcatepec Basin produced only negative evidence about
the occurrence of Pseudemys in the Río Tepalcatepec and Río Balsas. I
suspect that the best place to search for these turtles on the coast of
Michoacán is in the numerous fresh-water lagoons on the coastal plain.

Caiman crocodilus fuscus (Cope)

Gadow (1930:50) reported that Caiman sclerops (= Caiman crocodilus
fuscus) inhabited the “tierra caliente” in Michoacán. Smith and Taylor
(1950b:212) accepted Gadow’s record for the State, although otherwise
the species is unknown north of Oaxaca. Peters (1954:10) refuted Gadow’s
record on the basis that Gadow’s collections contained no specimens of
Caiman. The local name “caiman” refers to both Crocodylus and to
Caiman, for, in general, the natives do not distinguish between the
two. “Caimanes” are reported from along the coast of Michoacán, where
the name presumably refers to Crocodylus acutus acutus, and in the
Balsas-Tepalcatepec Basin (Gadow, 1930:50; Webber, 1946:267). I have
seen no specimens of either Crocodylus or Caiman from the Balsas
Basin. If crocodilians do occur in the basin, they probably are
Crocodylus acutus acutus. There is no basis, whatsoever, for including
Michoacán in the range of Caiman crocodilus fuscus.[Pg 127]

Bipes canaliculatus Bonnaterre

Dugès (1896:480) reported this species from Morelia, Michoacán. Smith
and Taylor (1950b:39), who recorded the species from three localities in
the Balsas Basin in Guerrero, rejected Dugès’ record. I, too, am
unwilling to accept Dugès’ record. Nevertheless, the species probably
occurs throughout much of the Balsas Basin. This idea is strengthened by
comments made by Storm (1939:342): “The last hard drop, that afternoon,
was down the great Cerro de los Cajones [southwest of Tacámbaro], and
here in the upper forest we came upon… a lizard with front legs and
none behind … the animal with hands and no feet that señor Smith
[Hobart M. Smith] was seeking!… They’re named Bipes caniculatus
(sic.).”

Coleonyx elegans nemoralis Klauber

Klauber (1945:199) and Smith and Taylor (1950b:43) reported this lizard
from the coastal lowlands of Colima and Guerrero. Davis and Smith
(1953:101) reported it from 8 kilometers northeast of Temilpa, Morelos,
in the upper Balsas Basin. Specimens of this lizard have been collected
infrequently; the few locality records and limited ecological data
indicate that it inhabits dense scrub forest and tropical semi-deciduous
forest. Coleonyx elegans nemoralis is to be expected on the coastal
lowlands, the seaward foothills of the Sierra de Coalcomán, and on the
lower slopes of the Cordillera Volcánica along the northern edge of the
Tepalcatepec Valley.

Phrynosoma orbiculare orbiculare (Linnaeus)

Gadow (1905:213) inferred that Phrynosoma orbiculare occurred at
elevations of more than 3000 feet in Michoacán. There are no specimens
of this species known from Gadow’s collections made in Michoacán. Smith
and Taylor (1950b:98) apparently accepted Gadow’s statement and recorded
the species from Michoacán: “above 3000 feet (Jorullo?).” Reeve
(1952:940) somehow misconstrued this statement to read “Jorullo, above
Zumpango (Smith and[Pg 128] Taylor, 1950b).” Reeve did not indicate on his map
(1952:939) that the species occurred in Michoacán. In the most recent
review of the species (Horowitz, 1955), no localities are given in
Michoacán. Since Phrynosoma orbiculare is known from central Jalisco,
Guanajuato, Queretaro, and México, its presence at least in northeastern
Michoacán is to be expected, although at the present time there are no
specimens known from the state.

Eumeces brevirostris (Günther)

Smith and Taylor (1950b:168) Listed this species: “Michoacán: No
specific record.” I am unaware of any specimen of this skink from the
state. As presently recognized, this species contains two subspecies.
One of these occurs in the mountains of Oaxaca northward into central
Veracruz; the other, Eumeces brevirostris bilineatus, occurs in
Durango southward to Jalisco, where it inhabits the Sierra Madre
Occidental. Possibly the species occurs in the Sierra de los Tarascos in
Michoacán.

Eumeces callicephalus Bocourt

Dugés (1896) in a paper in which he listed several species of Eumeces
in México, reported Eumeces callicephalus from Michoacán, but he gave
no specific locality within the state. Michoacán was included in the
range of the species by Taylor (1936:298) and by Smith and Taylor
(1950b:164). The species definitely is known from southeastern Arizona
southward to Guanajuato. It may occur in Michoacán, but, since there are
three rather widespread species of Eumeces inhabiting the Mexican
Plateau and associated mountain ranges in the northern and northeastern
part of Michoacán, interspecific competition might be a reason for the
absence of Eumeces callicephalus there.

Leptodeira septentrionalis polysticta Günther

Although this species occurs from sea level to elevations of about 2000
meters from Nayarit southward into Central America, no[Pg 129] specimens are
known from Michoacán. Smith and Taylor (1945:87) listed the species as
occurring in Michoacán, but they had no record on which to base this
report. Probably, the species occurs on the coastal lowlands and seaward
slopes of the Sierra de Coalcomán.

Tropidodipsas fasciata guerreroensis Taylor

Dugès (1896:480) reported a snake, questionably of this species, from
Uruapan, Michoacán. Taylor (1940c) suggested that on geographic grounds
Dugès’ record might refer to T. f. guerreroensis, which is known
definitely only from the type locality. Tropidodipsas occidentala is
known from Comala, Colima, and Coalcomán, Michoacán. On zoogeopraphic
grounds that species might be found at Uruapan. Since the specimen
apparently no longer is extant, the identification cannot be
ascertained.

Micrurus fitzingeri fitzingeri (Jan)

Smith and Taylor (1945:174) recorded the species from Zamora, Michoacán.
Hobart M. Smith (in litt.) stated that this record was based on a
report of Elaps fulvius from Zamora by Dugès (1896:482). Smith guessed
that the report was based on a specimen of Micrurus fitzingeri. The
specimen has not been seen. Although the species is known from
Guanajuato and México, until a specimen is available from Michoacán, the
species should not be considered part of the herpetofauna of Michoacán.

GAZETTEER

The localities in Michoacán here listed are those from which specimens
were examined as well as other localities mentioned in the text. The
localities are arranged alphabetically according to the most definitive
word or words in the total name. For example, Lago de Chapala is listed
as “Chapala (Lago de)” and Cerro de Tancítaro is listed as “Tancítaro
(Cerro de).” Insofar as has been possible, the following information is
given for each locality: geographical co-ordinates to the nearest minute
of north latitude and west longitude, elevation in meters above mean sea
level, a description of its geographical location, type of dominant
vegetation, and in some cases comments concerning collecting sites in
the vicinity. Distances are in kilometers; all are map (air line)
distances, unless otherwise indicated. Many localities visited on mule
trips are given as being a certain number of “mule hours” in a general
direction from another town or village. In order to reach most of these
localities today, one would have to go by mule, and this is the way the
muleteers determine their distances. Some of the elevations are taken
from maps, but most of them were obtained from one or more readings of
altimeters that we carried in the field. The terms used for describing
the vegetation are those defined in the section of the natural
landscape.[Pg 130]

Transcriber’s note: double click on the map to get a larger image.

Fig. 11. Map of Michoacán showing important localities
mentioned in text. Localities not on this map can be located by
directions given in the gazetteer.

[Pg 132]

My primary cartographic sources have been: the provisional edition of
maps published by the American Geographic Society (Colima, Guadalajara,
México, and San Luis Potosí sheets published between 1933 and 1940),
scale 1:1,000,000; the preliminary sheets (Colima, Guadalajara,
Guanajuato, and México) published in 1949 with a scale of 1:500,000 of
the Carta Geográfica de la República Méxicana (Dirección de Geografía y
Meterología, Secretaria de Agricultura y Ganadería); and the Carta de
Cuenca Tepalcatepec (Scale 1:250,000) prepared in 1958 by the Comisión
del Tepalcatepec, Secretaria de Recursos Hidráulicos. I have visited
most of the 181 localities and have gathered data pertaining to
vegetation, altitude, and location. I think, nevertheless, that the
accuracy of some of the locations and elevations as given in the
gazetteer is questionable. This situation can be rectified only by
detailed geographic studies.

Most of the important towns, villages, rivers, and high mountains are
shown on the accompanying map (Fig. 11). Places not shown on this map
can be located from directions given in the gazetteer.