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  UNIVERSITY OF KANSAS PUBLICATIONS
  MUSEUM OF NATURAL HISTORY

  Volume 15, No. 5, pp. 205-249, pls. 7-10, 6 figs.

  -------------- October 4, 1963 --------------

  Amphibians and Reptiles of the Rainforests
  of Southern El Petén, Guatemala

  BY
  WILLIAM E. DUELLMAN

  UNIVERSITY OF KANSAS
  LAWRENCE
  1963

  UNIVERSITY OF KANSAS PUBLICATIONS, MUSEUM OF NATURAL HISTORY

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

  Vol. 15, No. 5, pp. 205-249, pls. 7-10, 6 figs.
  Published October 4, 1963

  UNIVERSITY OF KANSAS
  Lawrence, Kansas

  PRINTED BY
  JEAN M. NEIBARGER, STATE PRINTER
  TOPEKA, KANSAS
  1963

  [Illustration: Printer's Logo]

  29-5935




  Amphibians and Reptiles of the Rainforests of Southern El Petén,
  Guatemala

  BY

  WILLIAM E. DUELLMAN




CONTENTS


                                                                    PAGE
  INTRODUCTION                                                       207
    Acknowledgments                                                  208

  DESCRIPTION OF AREA                                                208
    Physiography                                                     209
    Climate                                                          209
    Vegetation                                                       209

  GAZETTEER                                                          210

  THE HERPETOFAUNA OF THE RAINFOREST                                 211
    Composition of the Fauna                                         212
    Ecology of the Herpetofauna                                      212
    Relationships of the Fauna                                       217

  ACCOUNTS OF SPECIES                                                218

  HYPOTHETICAL LIST OF SPECIES                                       246

  SUMMARY                                                            247

  LITERATURE CITED                                                   247




INTRODUCTION


Early in 1960 an unusual opportunity arose to carry on biological field
work in the midst of virgin rainforest in southern El Petén, Guatemala.
At that time the Ohio Oil Company of Guatemala had an air strip and camp
at Chinajá, from which place the company was constructing a road
northward through the forest. In mid-February, 1960, J. Knox Jones, Jr.
and I flew into El Petén to collect and study mammals, reptiles, and
amphibians. While enjoying the comforts of the fine field camp at
Chinajá, we worked in the surrounding forest and availed ourselves of
the opportunity to be on hand when the road crews were cutting the tall
trees in the forest, thereby bringing to the ground many interesting
specimens of the arboreal fauna. We stayed at Chinajá until late March,
with the exception of a week spent at Toocog, another camp of the Ohio
Oil Company located 15 kilometers southeast of La Libertad and on the
edge of the savanna. Thus, at Toocog we were able to work both in the
forest and on the savanna. In the summer of 1960, John Wellman
accompanied me to El Petén for two weeks in June and July. Most of our
time was spent at Chinajá, but a few days were spent at Toocog and other
localities in south-central El Petén.

Many areas in Guatemala have been studied intensively by L. C. Stuart,
who has published on the herpetofauna of the forested area of
northeastern El Petén (1958), the savannas of central El Petén (1935),
and the humid mountainous region to the south of El Petén in Alta
Verapaz (1948 and 1950). The area studied by me and my companions is
covered with rainforest and lies to the north of the highlands of Alta
Verapaz and to the south of the savannas of central El Petén. A few
specimens of amphibians and reptiles were obtained in this area in 1935
by C. L. Hubbs and Henry van der Schalie; this collection, reported on
by Stuart (1937), contained only one species, _Cochranella
fleischmanni_, not present in our collection of 77 species and 617
specimens.


Acknowledgments

I am grateful to L. C. Stuart of the University of Michigan, who made
the initial arrangements for our work in El Petén, aided me in the
identification of certain specimens, and helped in the preparation of
this report. J. Knox Jones, Jr. and John Wellman were able field
companions, who added greatly to the number of specimens in the
collection. In Guatemala, Clark M. Shimeall and Harold Hoopman of the
Ohio Oil Company of Guatemala made available to us the facilities of the
company's camps at Chinajá and Toocog. Alberto Alcain and Luis Escaler
welcomed us at Chinajá and gave us every possible assistance. Juan
Monteras and Antonio Aldaña made our stay at Toocog enjoyable and
profitable. During our visits to southern El Petén, Julio Bolón C.
worked for us as a collector, and between March and June he collected
and saved many valuable specimens; his knowledge of the forest and its
inhabitants was a great asset to our work. Jorge A. Ibarra, Director of
the Museo Nacional de Historia Natural in Guatemala assisted us in
obtaining necessary permits and extended other kindnesses. To all of
these people I am indebted for the essential parts that they played in
the completion of this study.

Field work in the winter of 1960 was made possible by funds from the
American Heart Association for the purposes of collecting mammalian
hearts. My field work in the summer of 1960 was supported by a grant
from the Graduate Research Fund of the University of Kansas.




DESCRIPTION OF THE AREA


A vast lowland region stretches northward for approximately 700
kilometers from the highlands of Guatemala to the Gulf of Mexico. The
northern two-thirds of this low plain is bordered on three sides by seas
and forms the Yucatán Peninsula. The lowlands at the base of the
Yucatán Peninsula make up the Departamento El Petén of Guatemala. The
area with which this report is concerned consists of the south-central
part of El Petén.


Physiography

Immediately south of Chinajá is a range of hills, the Serrania de
Chinajá, having an almost due east-west axis and a crest of about 600
meters above sea level. South of the Serrania de Chinajá are
succeedingly higher ridges building up to the Meseta de Cobán and Sierra
de Pocolha and eventually to the main Guatemalan highlands. The northern
face of the Serrania de Chinajá is a fault scarp dropping abruptly from
about 650 meters at the crest to about 140 meters at the base. From the
base of the Serrania de Chinajá northward to the Río de la Pasión at
Sayaxché the terrain is gently rolling and has a total relief of about
50 meters. North of the Río de la Pasión is a low dome reaching an
elevation of 170 meters at La Libertad; see Stuart (1935:12) for further
discussion of the physiography of central El Petén. The rocks in
southern El Petén are predominately Miocene marine limestones; there are
occasional pockets of Pliocene deposits. There is little evidence of
subterranean solution at Chinajá, but northward in central El Petén
karsting is common. The upper few inches of soil is humus rich in
organic matter; below this is clay.


Climate

The climate of El Petén is tropical with equable temperatures throughout
the year. Temperatures at Chinajá varied between a night-time low of 65°
F. and a daytime high of 91° F. during the time of our visits. In the
Köppen system of classification the climate at Chinajá and Toocog is Af.
Rain falls throughout the year, but there is a noticeable dry season. To
anyone who has traveled from south to north in El Petén and the Yucatán
Peninsula, it is obvious from the changes in vegetation that there is a
decrease in rainfall from south to north. There is a noticeable
difference between Chinajá and Toocog. Although rainfall data are not
available for Chinajá and Toocog, there are records for nearby stations
(Sapper, 1932). At Paso Caballos on the Río San Pedro about 40
kilometers northwest of Toocog the average annual rainfall amounts to
1620 mm.; the driest month is March (21 mm.), and the wettest months are
June (269 mm.) and September (265 mm.). At Cubilquitz, Alta Verapaz,
about 35 kilometers south-southwest of Chinajá and at an elevation of
300 meters, the average annual rainfall is 4006 mm.; the driest month is
March (128 mm.), and the wettest months are July (488 mm.) and October
(634 mm.).

During the 18 days in February and March, 1960, that we kept records on
the weather at Chinajá moderate to heavy showers occurred on seven days.
During our stay there in June and July rain fell every day, as it did in
Toocog. However, during the week spent at Toocog in March no rain fell.


Vegetation

The vegetation of northern and central El Petén has been studied by
Lundell (1937), who made only passing remarks concerning the plants of
the southern part of El Petén. No floristic studies have been made
there. The following remarks are necessarily brief and are intended
only to give the reader a general picture of the forest. I have included
names of a few of the commoner trees that I recognized.

Chinajá is located in a vast expanse of unbroken rainforest. In this
forest there is a noticeable stratification of the vegetation. Three
strata are apparent; in the uppermost layer the tops of the trees are
from 40 to 50 meters above the ground. The spreading crowns of the trees
and the interlacing vines form a nearly continuous canopy over the lower
layers. Among the common trees in the upper stratum are _Calophyllum
brasiliense_, _Castilla elastica_, _Cedrela mexicana_, _Ceiba
pentandra_, _Didalium guianense_, _Ficus_ sp., _Sideroxylon lundelli_,
_Swietenia macrophylla_, and _Vitex_ sp. (Pl. 1, fig. 1). The middle
layer of trees have crowns about 25 meters above the ground; these trees
in some places where the upper canopy is missing form the tallest trees
in the forest. This is especially true on steep hillsides. Common trees
in the middle layer include _Achras zapote_, _Bombax ellipticum_,
_Cecropia mexicana_, _Orbignya cohune_, and _Sabal_ sp. The lowermost
layer reaches a height of about 10 meters; in many places in the forest
this layer is absent. Common trees in the lower stratum include
_Crysophila argentea_, _Cymbopetalum penduliflorum_, _Casearia_ sp., and
_Hasseltia dioica_.

The ground cover is sparce; apparently only a few small herbs and ferns
live on the heavily shaded forest floor. Important herpetological
habitats include the leaf litter, rotting stumps, and rotting tree
trunks on the forest floor and the buttresses of many of the gigantic
trees, especially _Ceiba pentandra_ (Pl. 2). Epiphytes, especially
various kinds of bromeliads, are common. Most frequently these are in
the trees in the upper and middle strata.

At Toocog there is sharp break between savanna and forest (Pl. 7, fig.
2). The forest is noticeably drier and more open than at Chinajá (Pl.
9). The crowns of the trees are lower, and there is no nearly continuous
canopy between 40 and 50 meters above the ground. Although _Swietenia
macrophylla_ and other large trees occur, they are less common than at
Chinajá. Especially common at Toocog are _Achras zapote_, _Brosimum
alicastrum_, and various species of _Ficus_.




GAZETTEER


The localities from which specimens were obtained are cited below and
shown on the accompanying map (Fig. 1).

[Illustration: FIG. 1. Map of El Petén, Guatemala, showing localities
mentioned in text.]

      Chinajá.--Lat. 16° 02´, long. 90° 13´, elev. 140 m. Camp of
      the Ohio Oil Company of Guatemala and formerly a small
      settlement. On some maps Chinajá is located just to the north
      of the Alta Verapaz--El Petén boundary; recent surveys place
      the location just to the south of the imaginary line through
      the rainforest. Field work was conducted in the immediate
      vicinity of the camp, on the lower slopes of the Serrania de
      Chinajá, and at several sites to the northwest and
      north-northwest of Chinajá, where the forest was being
      cleared. The entire area supports rainforest.

      La Libertad.--Lat. 16° 47´, long. 90° 07´, elev., 170 m. A
      town on the savannas in central El Petén; although we
      collected there in the rainy season, the specimens obtained on
      the savannas are not included in this report.

      Paso Subín.--Lat. 16° 38´, long. 90° 12´, elev. 90 m. A small
      settlement on the Río Subín, a tributary of the Río de la
      Pasión. Specimens were obtained in rainforest in the immediate
      vicinity of the settlement.

      Río de la Pasión.--A large river flowing northward through
      southern El Petén and thence westward into the Río Usumacinta.
      Specimens were obtained along the river between the Río Subín
      and Sayaxché.

      Río San Román.--A river flowing northward in south-central El
      Petén to the Río Salinas (Usumacinta). We collected along the
      river at a place about 16 kilometers north-northwest of
      Chinajá, approximately at Lat. 16° 10´, long. 90° 17´, elev.
      110 m. In the dry season the river was clear; it is surrounded
      by rainforest.

      Sayaxché.--Lat. 16° 31´, long. 90° 09´, elev. 80 m. A town on
      the southern bank of the Río de la Pasión. Specimens were
      obtained in the rainforest and in cleared areas in the
      immediate vicinity of the town.

      Toocog (formerly Sojío).--Lat. 16° 41´, long. 90° 02´, elev.
      140 m. A camp of the Ohio Oil Company of Guatemala located at
      the rainforest-savanna edge, 15 kilometers southeast of La
      Libertad. Although we collected on the savannas as well as in
      the forest, especially to the east of the camp, only species
      obtained in the forest are considered in this report.




THE HERPETOFAUNA OF THE RAINFOREST


In presenting an account of the herpetofauna of southern El Petén three
items need to be considered: (1) The composition of the fauna; (2) the
ecology of the fauna; (3) the relationships of the fauna. Each of these
topics is discussed briefly below. Logically a discussion of the origin
of the fauna should follow, but this is being withheld for inclusion in
a report on the herpetofauna of the entire El Petén by L. C. Stuart and
the author; at that time the above topics will be expanded to cover the
herpetofauna of the whole region.


Composition of the Fauna

TABLE 1.--COMPOSITION OF THE HERPETOFAUNA IN SOUTHERN EL PETÉN,
GUATEMALA.

  =============+============+============+============
      Group    |  Families  |   Genera   |  Species
  -------------+------------+------------+------------
  Gymnophiona  |     (1)[A] |    (1)     |    (1)
  Caudata      |     1      |    1       |    2
  Salientia    |     6      |   10 (1)   |   19 (1)
  Crocodilia   |     1      |    1       |    1
  Testudines   |     4      |    7       |    8
  Sauria       |     6      |   13 (1)   |   19 (1)
  Serpentes    |     4      |   21 (7)   |   29 (10)
               +------------+------------+------------
  Total        |    22 (1)  |   53 (10)  |   78 (13)
  -------------+------------+------------+------------

[Footnote A: Numbers in parenthesis indicate the number of additional
taxa that probably occur.]


A total of 78 species of amphibians and reptiles has been found in the
rainforests in southern El Petén; a break down into families and genera
is given in table 1. Another 13 species probably occur in southern El
Petén (see Hypothetical List of Species). The fauna primarily is
composed of typical humid lowland forest inhabitants, such as:

  _Hyla ebraccata_
  _Hyla loquax_
  _Phyllomedusa callidryas taylori_
  _Smilisca phaeota cyanosticta_
  _Anolis biporcatus_
  _Anolis capito_
  _Anolis humilis uniformis_
  _Eumeces sumichrasti_
  _Ameiva festiva edwardsi_
  _Imantodes cenchoa leucomelas_
  _Leptophis ahaetulla praestans_
  _Xenodon rabdocephalus mexicanus_
  _Bothrops nasutus_
  _Bothrops schlegeli schlegeli_

Nevertheless, the region also provides at least a limited amount of
habitat suitable for some species that are more frequently found in open
forest of a drier nature; such species include:

  _Hyla microcephala martini_
  _Hyla staufferi_
  _Hypopachus cuneus nigroreticulatus_
  _Anolis sericeus sericeus_
  _Eumeces schwartzei_
  _Oxybelis aeneus aeneus_

Because of the absence of sufficiently open habitat or owing to the
presence of competitors, some conspicuous members of sub-humid forests
are not present in southern El Petén. Conspicuous absentees are the
following:

  _Rhinophrynus dorsalis_
  _Phrynohyas spilomma_
  _Triprion petasatus_
  _Anolis tropidonotus_
  _Ctenosaura similis_
  _Ameiva undulata_
  _Cnemidophorus angusticeps_
  _Conophis lineatus_
  _Masticophis mentovarius mentovarius_

PLATE 7

[Illustration: FIG. 1. Edge of rainforest along airstrip at Chinajá, El
Petén, Guatemala.]

[Illustration: FIG. 2. Rainforest at edge of savanna at Toocog, El
Petén, Guatemala.]

PLATE 8

[Illustration: Interior of rainforest at Chinajá. Notice size of
buttresses on large tree (_Ceiba pentandra_).]

PLATE 9

[Illustration: Interior of rainforest at Toocog. Notice less dense
vegetation as compared with Pl. 8.]

PLATE 10

[Illustration: FIG. 1. Rainforest along Río San Román, 16 kilometers
north-northwest of Chinajá.]

[Illustration: FIG. 2. Rain pond in forest at Toocog. This was a
breeding site for six species of frogs.]


Ecology of the Herpetofauna

Our two visits to Chinajá and Toocog afforded the opportunity to gather
data on the ecology of the rainforests of southern El Petén and to study
the relationships between the environment and members of the
herpetofauna. Tropical rainforests present the optimum conditions
for life, and it is in this environment that life reaches its greatest
diversity. Here, too, biological inter-relationships are most complex.
This complexity is illustrated by the presence of many species of some
genera, all of which are found together in the same geographic region.
In the rainforests of southern El Petén there are six species of
_Anolis_, five of _Hyla_, four of _Bothrops_, and three of
_Coniophanes_. Obviously, the diversity of ecological niches in the
rainforest is sufficient to support a variety of related species. Of the
examples mentioned above, fairly adequate ecological data were obtained
for most of the species of _Anolis_, which will be used to show the
ecological diversity and vertical stratification of sympatric species in
the rainforests.

Of the six species of _Anolis_, all except _A. sericeus_ are typically
found in humid forests. _Anolis sericeus sericeus_ is poorly represented
in the collections from southern El Petén, where it may be in
competition with _Anolis limifrons rodriguezi_ that resembles _Anolis s.
sericeus_ in size, coloration, and habits. Therefore, _Anolis sericeus
sericeus_ is excluded from the following discussion. The common
terrestrial species is _Anolis humilis uniformis_; sometimes this small
species perches or suns on the bases of small trees or buttresses of
some large trees. When disturbed it takes to the ground and seeks cover
in the leaf litter or beneath logs or palm fronds. _Anolis lemurinus
bourgeaei_ is about twice the size of _Anolis humilis uniformis_ and is
usually observed on buttresses of large trees or on the lower two meters
of tree trunks. Individuals were seen foraging on the ground along with
_Anolis humilis uniformis_. At no time were _Anolis lemurinus bourgeaei_
observed to ascend the trunks of large trees; they always took refuge
near the bases of trees. _Anolis limifrons rodriguezi_ is found on the
stems and branches of bushes. It is a small species that sometimes is
observed on the ground but was never seen ascending large trees. _Anolis
capito_ is about the same size as _Anolis lemurinus bourgeaei_ and lives
on the trunks of large trees. In the tops of the trees lives a large
green species, _Anolis biporcatus_.

Similar segregation habitatwise can be demonstrated for other members of
the herpetofauna. The avoidance of interspecific competition in feeding
is well illustrated by three species of snakes that probably are the
primary ophidian predators on frogs. _Drymobius margaritiferus
margaritiferus_ is diurnal and terrestrial; it feeds on frogs at the
edges of breeding ponds by day. Also during the day _Leptophis mexicanus
mexicanus_ feeds on frogs in bushes and trees. At night the activities
of both of these species is replaced by those of _Leptodeira
septentrionalis polysticta_, which not only feeds on the frogs in the
trees and bushes, but descends to the ground and even enters the water
in search of food.

From the examples discussed above, the importance of the three
dimensional aspect of the rainforest is apparent. The presence of a
large and diverse habitat above the ground is of great significance in
the rainforest, for of the non-aquatic components of the herpetofauna in
the rainforests of southern El Petén, 42 per cent of the species spend
at least part of their lives in the bushes and trees. Another important
part of the forest is the subterranean level--the rich mulch,
underground tunnels, and rotting subterranean vegetation. Of the 78
species of amphibians and reptiles in southern El Petén, seven are
primarily fossorial, and half-a-dozen others are secondarily fossorial.
Probably the fossorial members of the fauna are the least well
represented in the collection, for such widespread species as _Dermophis
mexicanus mexicanus_, _Rhadinaea decorata decorata_ and _Tantilla
schistosa schistosa_ were expected, but not found.

In the following discussion of the ecological distribution of amphibians
and reptiles in the rainforest I have depended chiefly on my
observations made in southern El Petén, but have taken into
consideration observations made on the same species in other regions,
together with reports from other workers. The reader should keep in mind
that the evidence varies from species to species. Of some species I have
observed only one animal in the field; of others, I have seen scores and
sometimes hundreds of individuals. For species on which I have few
observations or rather inconclusive evidence, the circumstance of
inadequate data is mentioned.

In analyzing the ecological distribution within the forest, it is
convenient to recognize five subdivisions (habitats); each is treated
below as a unit.

1. AQUATIC.--This habitat includes permanent streams and rivers (Pl. 10,
fig. 1), some of which are clear and others muddy. In the rainy season
temporary ponds form in depressions on the forest floor (Pl. 10, fig.
2); these are important as breeding sites for many species of
amphibians. Aquatic members of the herpetofauna are here considered to
be those species that either spend the greatest part of their lives in
the water or usually retreat to water for shelter. Seven species of
turtles and one crocodilian are aquatic. Of these, _Dermatemys mawi_,
_Staurotypus triporcatus_, and _Pseudemys scripta ornata_ inhabit clear
water, whereas _Chelydra rossignoni_, _Claudius angustatus_,
_Kinosternon acutum_, and _K. leucostomum_ inhabit muddy water.
_Crocodylus moreleti_ apparently inhabits both clear and muddy water,
for in the dry season it lives along the clear rivers, but in the rainy
season inhabits flooded areas in the forest as well.

2. AQUATIC MARGIN.--Extensive marshes were lacking in the part of
southern El Petén that I visited; consequently, the aquatic margin
habitat is there limited to the edges of rivers and borders of temporary
ponds. _Bufo marinus_, _Rana palmipes_, and _Rana pipiens_ are
characteristic inhabitants of the aquatic margin, although in the rainy
reason _Bufo marinus_ often is found away from water. Observations
indicate that _Tretanorhinus nigroluteus lateralis_ inhabits the margins
of ponds and streams and actually spends considerable time in the water.
Although _Iguana iguana rhinolopha_ is arboreal, it lives in trees along
rivers, into which it plunges upon being disturbed. Species included in
this category are those that customarily spend most of their lives at
the edge of permanent water. Frogs and toads that migrate to the water
for breeding and the snakes that prey on the frogs at that time are not
assigned to the aquatic-margin habitat.

3. FOSSORIAL.--Characteristic inhabitants of the mulch on the forest
floor are _Bolitoglossa moreleti mulleri_, _Lepidophyma flavimaculatum
flavimaculatum_, _Scincella cherriei cherriei_, _Ninia sebae sebae_,
_Pliocercus euryzonus aequalis_, and _Micrurus affinis apiatus_. Other
species of snakes that spend most of their lives above ground often
forage in the mulch layer; among these are _Coniophanes bipunctatus
biserialis_, _Coniophanes fissidens fissidens_, _Coniophanes imperialis
clavatus_, _Lampropeltis doliata polyzona_, and _Stenorrhina
degenhardti_. Among the amphibians, at least _Hypopachus cuneus
nigroreticulatus_, _Eleutherodactylus rostralis_, and _Syrrhophus
leprus_ are known to seek shelter in the mulch.

4. TERRESTRIAL.--One turtle, _Geoemyda areolata_, is primarily
terrestrial. Among the lizards, conspicuous terrestrial species are
_Anolis humilis uniformis_ and _Ameiva festiva edwardsi_; _Anolis
lemurinus bourgeaei_ and _Basiliscus vittatus_ spend part of their lives
on the ground, but also live on trees and in bushes. _Eumeces
schwartzei_ and _E. sumichrasti_ apparently are terrestrial. The only
terrestrial lizard that is nocturnal is _Coleonyx elegans elegans_,
which by day hides in the leaf litter or below ground. Nocturnal
amphibians that are terrestrial include _Bufo marinus_, _Bufo valliceps
valliceps_, _Eleutherodactylus rugulosus rugulosus_, _Syrrhophus
leprus_, and _Hypopachus cuneus nigroreticulatus_. A large number of
active diurnal snakes are terrestrial; these include _Boa constrictor
imperator_, _Clelia clelia clelia_, _Dryadophis melanolomus laevis_,
_Drymarchon corais melanurus_, _Drymobius margaritiferus
margaritiferus_, _Pseustes poecilonotus poecilonotus_, and _Spilotes
pullatus mexicanus_. Nocturnal terrestrial snakes include three kinds of
_Bothrops_ (_B. atrox asper_, _B. nasutus_, and _B. nummifer nummifer_),
all of which seem to be equally active by day.

5. ARBOREAL.--In this habitat the third dimension (height) of
the rainforest probably is the most complex insofar as the
inter-relationships of species and ecological niches are concerned. I
have attempted to categorize species as to microhabitats within the
arboreal habitat; in so doing, I recognize four subdivisions--bushes,
tree trunks, tree tops, and epiphytes.

Bush inhabitants include several species of lizards and snakes, all of
which have rather elongate, slender bodies, and long tails. Common
bush-inhabitants in southern El Petén are _Anolis limifrons rodriguezi_,
_Basiliscus vittatus_, _Laemanctus deborrei_, _Leptophis mexicanus
mexicanus_, and _Oxybelis aeneus aeneus_. All of these are diurnal, and
all but _Laemanctus_ have been observed sleeping on bushes at night.

Tree-trunk inhabitants include five species of lizards. _Thecadactylus
rapicaudus_ lives on the trunks of large trees; _Sphaerodactylus
lineolatus_ lives beneath the bark on dead trees and on corozo palms.
_Anolis lemurinus bourgeaei_ lives on the bases and buttresses of large
trees, from which it often descends to the ground. _Corythophanes
cristatus_ and _Anolis capito_ were found only on tree trunks and large
vines.

The least information is available for the species living in the tree
tops. The following species were obtained from tops of trees when they
were felled, or have been observed living in the tree tops: _Anolis
biporcatus_, _Iguana iguana rhinolopha_, _Celestus rozellae_,
_Leptodeira septentrionalis polysticta_, _Leptophis ahaetulla
praestans_, _Sibon dimidiata dimidiata_, and _Sibon nebulata nebulata_.

Epiphytes, especially the bromeliads, provide refuge for a variety of
tree frogs and small snakes. Of the tree frogs, _Hyla picta_, _Hyla
staufferi_, _Phyllomedusa callidryas taylori_, _Similisca baudini_, and
_Similisca phaeota cyanosticta_ have been found in bromeliads; other
species probably occur there. Among the snakes, _Imantodes cenchoa
leucomelas_, _Leptodeira frenata malleisi_, _Leptodeira septentrionalis
polysticta_, _Sibon dimidiata dimidiata_, and _Sibon nebulata nebulata_
are frequent inhabitants of bromeliads; all of these snakes are
nocturnal.


Relationships of the Fauna

Most of the 78 species of amphibians and reptiles definitely known from
the rainforest in southern El Petén have extensive ranges in the
Atlantic lowlands of southern México and Central America; many extend
into South America. Sixty-two (80%) of the species belong to this group
having extensive ranges in Middle America. Three species (_Syrrhophus
leprus_, _Leptodeira frenata_, and _Kinosternon acutum_) are at the
southern limits of their distributions in southern El Petén and northern
Alta Verapaz, whereas _Eleutherodactylus rostralis_ and _Thecadactylus
rapicaudus_ are at the northern and western limits of their
distributions in El Petén. Nine (11%) species have the center of their
distributions in El Petén and the Yucatán Peninsula; representatives of
this group include _Claudius angustatus_, _Dermatemys mawi_, _Laemanctus
deborrei_, and _Eumeces schwartzei_.

In determining a measure of faunal resemblance, I have departed from the
formulae discussed by Simpson (1960) and have analyzed the degree of
resemblance by the following formula used to calculate an index of
faunal relationships:

      C (2) / (N_{1} + N_{2}) = R, where

      C = species common to both faunas.

      N_{1} = number of species in the first fauna.

      N_{2} = number of species in the second fauna.

      R = degree of relationships (when R = 1.00, the faunas are
      identical; when R = 0, the faunas are completely different).

The herpetofauna of southern El Petén has been compared with that in the
Tikal-Uaxactún area (Stuart, 1958), that in the humid lowlands of Alta
Verapaz (Stuart, 1950, plus additional data), and that in the Mexican
state of Yucatán (Smith and Taylor, 1945, 1948, and 1950). The
herpetofaunas of lowland Alta Verapaz and Yucatán are the largest,
having respectively 94 and 91 species, where as there are 78 species
known from southern El Petén and 64 from the Tikal-Uaxactún area. An
analysis of faunal relationships (Table 2) shows that the faunas of the
rainforests of southern El Petén and lowland Alta Verapaz are closely
related. The relationships between these two areas and the
Tikal-Uaxactún area in northern El Petén is notably less. Apparently
the biggest faunal changes take place between southern El Petén and the
Tikal-Uaxactún area, and between the latter and Yucatán. As stated by
Stuart (1958:7) the Tikal-Uaxactún is transitional between the humid
rainforests to the south and the dry outer end of the Yucatán Peninsula.
The transitional nature of the environment is exemplified by a rather
depauperate herpetofauna consisting of some species of both dry and
humid environments and lacking a large fauna typical of either.
Contrariwise, the continuity of the environment from southern El Petén
to the lowlands of Alta Verapaz is reflected in degree of resemblance of
the herpetofaunas.

TABLE 2.--INDEX OF FAUNAL RELATIONSHIPS BETWEEN SOUTHERN EL PETÉN AND
OTHER REGIONS.

  ======================+==========+==========+==========+==========
                        | Lowland  | Southern |  Tikal-  |
                        |   Alta   |    El    | Uaxactún | Yucatán
                        | Verapaz  |  Petén   |   Area   |
  ----------------------+----------+----------+----------+----------
  Lowland Alta Verapaz  |          |    .85   |    .61   |    .43
  ----------------------+----------+----------+----------+----------
  Southern El Petén     |    .85   |          |    .64   |    .41
  ----------------------+----------+----------+----------+----------
  Tikal-Uaxactún Area   |    .61   |    .64   |          |    .63
  ----------------------+----------+----------+----------+----------
  Yucatán               |    .43   |    .41   |    .63   |
  ----------------------+----------+----------+----------+----------

Most of the species of amphibians and reptiles found in southern El
Petén are found in humid tropical forests from the Isthmus of
Tehuantepec southeastward on the Atlantic lowlands well into Central
America.




ACCOUNTS OF SPECIES


In the following pages various aspects of the occurrence, life
histories, ecology, and variation of the species of amphibians and
reptiles known from southern El Petén are discussed. Only _Cochranella
fleischmanni_ reported by Stuart (1937) from Río Subín at Santa Teresa
was not collected by us and is excluded. Because more worthwhile
information was gathered for some species than others, the length and
completeness of the accounts vary. All specimens listed are in the
Museum of Natural History at the University of Kansas, to which
institution all catalog numbers refer. Preceding the discussion of each
species is an alphabetical list of localities from which specimens were
obtained; numbers after a locality indicate the number of specimens
obtained at each locality.


=Bolitoglossa dofleini= (Werner)

      Chinajá, 1.

An adult female having minute ovarian eggs has a snout-vent length of 81
mm., a tail length of 59 mm., 13 costal grooves, two intercostal spaces
between adpressed toes, 38-35 vomerine teeth in irregular rows forming a
broad arch from a point posterolaterad to the internal nares to a point
near the anterior edge of the parasphenoid teeth, and 43-44
maxilliary-premaxillary teeth. In life the dorsum was rusty brown with
irregular black and orange spots and streaks. The flanks were bluish
gray with black in the costal grooves and creamy tan flecks along the
ventral edge of the flank. The belly and underside of the tail were
yellowish tan with dark brown spots laterally. The limbs were orange
proximally and black distally; the pads of the feet were bluish black.
The dorsal and lateral surfaces of the tail were yellowish orange with
black spots. The iris was grayish yellow.

Stuart (1943:17) reported this species from Finca Volcán, Alta Verapaz.
He diagnosed his specimens as having 13 costal grooves and two or three
intercostal spaces between adpressed toes. He stated that the vomerine
teeth were about 12 in number and that in life the dorsum was mottled
gray and black, the sides gray and brown, and the undersurfaces
uniformly dark gray. These specimens differ noticeably from the
individual from Chinajá in the number of vomerine teeth and in
coloration.

In August, 1961, I obtained a specimen of _Bolitoglossa dofleini_ at
Finca Los Alpes, Alta Verapaz, approximately 13 kilometers airline
south-southwest of Finca Volcán and at approximately the same elevation.
Although the salamander was dead when found, it obviously was more
heavily pigmented than the individual from Chinajá. The belly was bluish
gray with black spots laterally; the dorsum was dull brownish gray with
some brownish red streaks. The specimen is a female having small ovarian
eggs, a snout-vent length of 90 mm., 13 costal grooves, and two
intercostal spaces between adpressed limbs. There are 28-29 vomerine
teeth, more than twice as many as in specimens from Finca Volcán
(Stuart, 1943:17), but noticeably fewer than in the specimen from
Chinajá.

The presence of this species at Chinajá lends support to the idea that
the specimen from the Río de la Pasión listed by Brocchi (1882:116)
also is _Bolitoglossa dofleini_. Furthermore, the confirmed presence of
this species in the lowlands of El Petén suggests that there may be
genetic connection between _B. dofleini_ in the Alta Verapaz and _B.
yucatana_ in the Yucatán Peninsula. _Bolitoglossa yucatana_ differs from
_B. dofleini_ in having five intercostal spaces between adpressed toes
and in having a different color pattern. Both are robust species having
no close relationships to other species of _Bolitoglossa_ in northern
Central America.

The specimen from Chinajá was found in water in the axil of a large
elephant-ear plant (_Xanthosoma_) by day in March. Its stomach contained
fragments of beetles and a large roach. The natives did not know
salamanders and had no name for them.


=Bolitoglossa moreleti mulleri= (Brocchi)

      Chinajá, 2; Río San Román, 1.

One specimen is a female having a snout-vent length of 80 mm., a tail
length of 82 mm., and a total length of 162 mm. It contains 63 large
eggs, the largest of which has a diameter of about three millimeters.
This specimen has 13 costal grooves, four intercostal spaces between
adpressed toes, and 12-13 vomerine teeth. A juvenile having a snout-vent
length of 39 mm. and a tail length of 33 mm. has 12 costal grooves,
three intercostal spaces between adpressed toes, and 8-8 vomerine teeth.
In life these salamanders were uniformly dull brownish black above with
a dull creamy yellow irregular dorsal stripe beginning on the occiput
and continuing onto the tail. There are no yellow or orange streaks or
flecks on the head or limbs. The specimen from the Río San Román was
taken from the stomach of a _Pliocercus euryzonus aequalis_ and has not
been studied in detail, because of its poor condition.

The present specimens show no tendency for the development of a broad
irregular dorsal band that encloses black spots or forms irregular
dorsolateral stripes, as is characteristic of _B. moreleti mexicanus_, a
subspecies that has been reported from La Libertad (Stuart, 1935:35) and
Piedras Negras (Taylor and Smith, 1945:545) in El Petén, and from
Xunantunich, British Honduras (Neill and Allen, 1959:20).

Schmidt (1936:151) and Stuart (1943:13) found _B. moreleti mulleri_ in
bromeliads at Finca Samac, Alta Verapaz. Taylor and Smith's (1945:545)
and Neill and Allen's (1959:20) specimens of _B. moreleti mexicanus_
were obtained from bromeliads, but Neill and Allen (_loc. cit._) stated
that the natives in British Honduras said that they had found
salamanders beneath rubbish on the forest floor. My specimens were
obtained from beneath logs on the forest floor in the rainy season.
Possibly in drier environments the species characteristically inhabits
bromeliads, at least in the dry season.


=Bufo marinus= (Linnaeus)

      Chinajá, 3; 10 km. NNW of Chinajá, 1; 11 km. NNW of Chinajá,
      1.

During both visits to Chinajá this large toad was breeding in a small
permanent pond in the camp. During the day the toads took refuge in
crevices beneath the buildings or beneath large boulders by the pond. At
dusk from four to ten males congregated at the pond and called. Tadpoles
of this species were in the pond in March and in July. One juvenile was
found beneath a rock in the forest, and another was on the forest floor
by day.

The natives' name for this species and the following one is _sapo_.


=Bufo valliceps valliceps= Wiegmann

      Chinajá, 52; Río San Román, 8; Sayaxché, 2; Toocog, 1.

This is one of the most abundant, or at least conspicuous, amphibians
inhabiting the forest. Breeding congregations were found on February 24,
March 2, March 11, and June 27. At these times the toads were
congregated at temporary ponds in the forest or along small sluggish
streams. Throughout the duration of both visits to Chinajá individual
males called almost nightly at the permanent pond at the camp.

The variation in snout-vent length of 20 males selected at random is
56.7 to 72.5 mm. (average, 64.8 mm.). Two adult females have snout-vent
lengths of 80.4 and 87.6 mm. In all specimens the parotid glands are
somewhat elongated and not rounded as in _Bufo valliceps wilsoni_ (see
Baylor and Stuart, 1961:199). My observations on the condition of the
cranial crests of the toads in El Petén agree with the findings of
Baylor and Stuart (_op. cit._:198) in that hypertrophied crests are
usual in large females. In the shape of the parotids and nature of the
cranial crests the specimens from El Petén are like those from the
Isthmus of Tehuantepec in México. As I pointed out (1960:53), the
validity of the subspecies _Bufo valliceps macrocristatus_, described
from northern Chiapas by Firschein and Smith (1957:219) and supposedly
characterized by hypertrophied cranial crests, is highly doubtful.

In the toads from El Petén the greatest variation is in coloration. The
dorsal ground-color varies from orange and rusty tan to brown, yellowish
tan, and pale gray. In some individuals the flanks and dorsum are one
continuous color, whereas in others a distinct dorsolateral pale colored
band separates the dorsal color from dark brown flanks. In some
individuals the venter is uniform cream color, in others it bears a few
scattered black spots, and in still others there are many spots, some of
which are fused to form a black blotch on the chest. In breeding males
the vocal sac is orange tan. All specimens have a coppery red iris.

Aside from the breeding congregations, active toads were found on the
forest floor at night; a few were there by day. Some individuals were
beneath logs during the day.


=Eleutherodactylus rostralis= (Werner)

      Chinajá, 10.

Because of the multiplicity of names and the variation in coloration,
the small terrestrial _Eleutherodactylus_ in southern México and
northern Central America are in a state of taxonomic confusion. Stuart
(1934:7, 1935:37, and 1958:17) referred specimens from El Petén to
_Eleutherodactylus rhodopis_ (Cope). Stuart (1941b:197) described
_Eleutherodactylus anzuetoi_ from Alta Verapaz and El Quiché, Guatemala,
suggested that the new species was an upland relative of
_Eleutherodactylus rostralis_ (Werner), and used that name for the frogs
that he earlier had referred to _Eleutherodactylus rhodopis_. Dunn and
Emlen (1932:24) placed _E. rostralis_ in the synonymy of _E. gollmeri_
(Peters). Examination of series of these frogs from southern México,
Guatemala, and Costa Rica causes me to think that there are four
species; these can be distinguished as follows:

      _E. rhodopis._--No web between toes; one tarsal tubercle;
      tibiotarsal articulation reaches to nostril; iris bronze in
      life.

      _E. anzuetoi._--No web between toes; a row of tarsal
      tubercles; tibiotarsal articulation reaches to tip of snout;
      color of iris unknown.

      _E. rostralis._--A vestige of web between toes; no tarsal
      tubercles; tibiotarsal articulation reaches snout or slightly
      beyond; iris coppery red in life.

      _E. gollmeri._--A vestige of web between toes; no tarsal
      tubercles; tibiotarsal articulation reaches well beyond snout;
      iris coppery red in life.

The presence of webbing between the toes, the absence of tarsal
tubercles, and the coppery red iris distinguish _E. rostralis_ and _E.
gollmeri_ from the other species. Probably _E. rostralis_ and _E.
gollmeri_ are conspecific, but additional specimens are needed from
Nicaragua and Honduras to prove conspecificity. On the other hand, the
characters of the frogs from Chinajá clearly show that they are related
to _E. gollmeri_ to the south and not to _E. rhodopis_ to the north in
México.

At Chinajá, _Eleutherodactylus rostralis_ was more abundant than the
few specimens indicate, for upon being approached the frogs moved
quickly and erratically, soon disappearing in the leaf litter on the
forest floor. Most of the specimens were seen actively moving on the
forest floor in the daytime; one was found beneath a rock, and one was
on the forest floor at night.


=Eleutherodactylus rugulosus rugulosus= (Cope)

      Chinajá, 2; 15 km. NW of Chinajá, 4.

These frogs were found on the forest floor by day. With the exception of
one female having a snout-vent length of 69.5 mm., all are juveniles.
The apparent rarity of this species at Chinajá may be due to the absence
of rocky streams, a favorite habitat of this frog. The local name for
this frog is _sapito_, meaning little toad.


=Leptodactylus labialis= (Cope)

      Toocog, 1.

One juvenile having a snout-vent length of 16.4 mm. was found at night
beside a pond in the forest. The scarcity of the species of
_Leptodactylus_ in the southern part of El Petén probably is due to the
lack of permanent marshy ponds.


=Leptodactylus melanonotus= (Hallowell)

      Sayaxché, 1.

One individual was found beneath a rock beside a stream in the forest.
The local name is _ranita_, meaning little frog.


=Syrrhophus leprus= Cope

      Chinajá, 2; 15 km NW of Chinajá, 1.

An adult female having a snout-vent length of 27.5 mm. was found on the
forest floor by day. Two juveniles having snout-vent lengths of 15.5 and
19.0 mm. were beneath rocks on the forest floor. The specimens are
typical of the species as defined by Duellman (1958:8).


=Hyla ebraccata= Cope

      Toocog, 66.

This small tree frog congregated in large numbers at a forest pond at
Toocog. Between June 30 and July 2 we collected specimens and observed
the breeding habits of this and other species at the pond. Calling males
were distributed around the pond, where they called from low herbaceous
vegetation at the edge of the pond or from plants rising above the
water. Calling commenced at dusk and continued at least into the early
hours of the morning. On one occasion a female was observed at a
distance of about 50 centimeters away from a calling male sitting on a
blade of grass. The female climbed another blade of grass until she was
about eight centimeters away from the male, at which time he saw her,
stopped calling, jumped to the blade of grass on which she was sitting
and clasped her. Clasping pairs were observed on blades of grass and
leaves of plants above the water; most pairs were less than 50
centimeters above the surface of the pond.

The eggs are deposited on the dorsal surfaces of leaves above the water.
All eggs are in one plane (a single layer) on the leaf. External
membranes are barely visible, as the eggs consist of a single coherent
mass. Eggs in the yolk plug stage have diameters of 1.2 to 1.4 mm.
Seventeen eggs masses were found; these contained from 24 to 76 (average
44) eggs. The jelly is extremely viscous and tacky to the touch. At time
of hatching the jelly becomes less viscous; the tadpoles wriggle until
they reach the edge of the leaf and drop into the water.

Eleven tadpoles were preserved as they hatched; these have total lengths
of 4.5 to 5.0 (average 4.77) mm. Hatchling tadpoles are active swimmers
and have only a small amount of yolk. The largest tadpoles preserved
have total lengths of 13.0 and 13.5 mm. At this size distinctive
sword-tail and bright coloration have developed.

[Illustration: FIG. 2. Tadpole of _Hyla ebraccata_ (KU 59986) from
Toocog, El Petén, Guatemala. × 6.]

Description of fully developed tadpole (KU 59986): Total length, 13.5
mm.; tail-length, 8.4 mm., 62 per cent of total length. Snout, in dorsal
view, bluntly rounded; in lateral view less bluntly rounded; body
depressed; head flattened; mouth terminal; eye large, its diameter 25
per cent of length of body; nostrils near tip of snout and directed
anteriorly; spiracle sinistral and situated postero-ventrad to eye;
cloaca median. Tail-fin thrice depth of tail-musculature, which extends
beyond posterior end of tail-fin giving sword-tail appearance (Fig. 2).
In life, black stripe on each side of body and on top of head; black
band on anterior part of tail and another on the posterior part; body
and anterior part of tail creamy yellow; dark red band between black
bands on tail. Mouth terminal, small, its width about one-fifth width of
body; fleshy ridge dorsally and ventrally; row of small papillae on
ventral lip; no lateral indentations of lips; upper beak massive,
convex, and finely serrate; lower beak small and mostly concealed behind
upper; no teeth (Fig. 3).

[Illustration: FIG. 3. Mouthparts of larval _Hyla ebraccata_ (KU 59986)
from Toocog, El Petén, Guatemala. × 100.]


=Hyla loquax= Gaige and Stuart

      Toocog, 14.

These specimens were found at night when they were calling from low
vegetation in a forest pond. Most of the frogs were several meters away
from the edge of the pond. Although two clasping pairs were found, we
obtained no eggs or tadpoles referable to this species.


=Hyla microcephala martini= Smith

      Chinajá, 1; Toocog, 21.

The specimen from Chinajá was calling from a small bush at the edge of a
temporary grassy pond in a clearing in the forest. At Toocog this
species was closely associated with _Hyla ebraccata_; males were calling
from herbaceous vegetation in and around the forest pond. These frogs
were not so abundant in the forest at Toocog as they were around ponds
on the savanna at La Libertad.


=Hyla picta= (Günther)

      Toocog, 8.

This small tree frog was calling from herbs in a pond in the forest on
June 30 and July 2. The voice is weak; probably greater numbers of males
were present than are indicated by the few specimens collected, for the
din from the more vociferous species made it impossible to hear _Hyla
picta_ unless one was calling close by.


=Hyla staufferi= Cope

      Chinajá, 1.

This individual was calling from a low bush in the clearing at Chinajá.
None was found in the pond in the forest at Toocog. Stuart (1935:38) and
Duellman (1960:63) noted that _Hyla staufferi_ breeds early in the rainy
season. Nevertheless, I think early breeding habits do not account for
the near absence of this species in our collections from southern El
Petén. In early July, 1960, a few individuals were heard at a pond on
the savanna at La Libertad. In mid-July of the same year they were
calling sporadically from temporary ponds in the lower Motagua Valley.
Possibly the individual collected at Chinajá was accidentally
transported there in cargo from Toocog, from which camp at the edge of
the savanna planes fly to Chinajá weekly. My observations on this
species throughout its range in México and Central America indicate that
it inhabits savannas and semi-arid forests and usually is absent from
heavy rainforest. Stuart (1948:34) obtained this species at Cubilquitz
in the lowlands of Alta Verapaz.


=Phyllomedusa callidryas taylori= Funkhouser

      Toocog, 25.

Between June 30 and July 2 this species was abundant at a pond in the
forest at Toocog. Calling males were as high as five meters in bushes
and trees around the pond. At dusk males were observed descending a
vine-covered tree at the edge of the pond; this strongly suggests that
the frogs retreat to this tree and others like it for diurnal seclusion.
Clasping pairs were found on branches and leaves above the water. The
eggs are deposited in clumps usually on vertical leaves, but sometimes
on horizontal leaves or on branches, vines, and aerial roots above the
water. Twenty-six clutches of eggs contained from 14 to 44 (average 29)
eggs. In a clutch in which the eggs are in yolk plug stage the average
diameter of the embryos is 2.3 mm. and that of the vitelline membranes,
3.4 mm. Most of the eggs are in the external part of the gelatinous
mass; the jelly is clear. The yolk is pale green, and the animal pole is
brown. As development ensues, the yolk becomes yellow and the embryo
first dark brown and then pale grayish tan. Upon hatching the tadpoles
wriggle free of the jelly and drop into the water. One clutch of 19 eggs
was observed to hatch in three minutes. Apparently, on dropping into the
water the hatchling tadpoles go to the bottom of the pond, for one or
two minutes pass from the time they enter the water until they reappear
near the surface. The average total length of seven hatchling tadpoles
is 7.4 mm. There is a moderate amount of yolk, but this does not form a
large ventral bulge. Large tadpoles congregate in the sunny parts of the
pond, where they were observed just beneath the surface. Many had their
mouths at the surface. Except for constant fluttering of the tip of the
tail, they lie quietly with the axis of the body at an angle of about 45
degrees with the surface of the water.

Description of tadpole (KU 60006): total length, 24.5 mm.; tail-length,
15.4 mm.; body broader than deep; head moderately flattened; snout
viewed from above blunt; nostrils close to snout and directed dorsally;
eyes of moderate size and directed laterally; mouth directed
anteroventrally; anus median; spiracle ventral, its opening just to left
of midline slightly more than one-half distance from tip of snout to
vent. Tail-fin slightly more than twice as deep as tail musculature,
which curves upward posteriorly; tail-fin narrowly extending to tip of
tail (Fig. 4). Color in life pale gray; in preservative white with
scattered melanophores; tail-fin transparent.

[Illustration: FIG. 4. Tadpole of _Phyllomedusa callidryas taylori_ (KU
60006) from Toocog, El Petén, Guatemala. × 4.]

Upper lip having single row of papillae laterally, but none medially;
lower lip having single row of papillae; no lateral indentation of lips;
two or more rows of papillae at lateral corners of lips; tooth-rows 2/3;
second upper tooth row as long as first, interrupted medially; inner
lower tooth-row as long as upper rows, interrupted medially; second and
third lower rows decreasingly shorter; upper beak moderate in size and
having long lateral projections; lower beak moderate in size; both beaks
finely serrate (Fig. 5).

[Illustration: FIG. 5. Mouthparts of larval _Phyllomedusa callidryas
taylori_ (KU 60006) from Toocog, El Petén, Guatemala. × 30.]


=Smilisca baudini= (Duméril and Bibron)

      Chinajá, 9; 20 km. NNW of Chinajá, 42; Río de la Pasión, 1;
      Río San Román, 5; Sayaxché; Toocog, 2.

Individuals of this species were found at night sitting on bushes and
small trees in the forest in February and March and again in June and
July. One was in the axil of a leaf of a _Xanthosoma_. In June and July
males were heard nearly every night. The series of specimens from 20
kilometers north-northwest of Chinajá was taken from a breeding
congregation in a shallow muddy pool in the forest. Tadpoles of this
species were in small, often muddy pools in the forest. To my knowledge
_Smilisca baudini_ is the only hylid to breed in these pools at Chinajá,
although perhaps _Smilisca phaeota_ also utilizes them. The only other
amphibian at Chinajá known to breed in the pools is _Bufo valliceps
valliceps_. Although two specimens were on bushes at night at Toocog,
_Smilisca baudini_ was not present at the pond where five other species
of hylids were breeding. Nevertheless, _Smilisca baudini_ was calling
from two ponds on the savannas near La Libertad. All of the specimens
from southern El Petén have yellow or yellowish white flanks and
ventrolateral surfaces.


=Smilisca phaeota cyanosticta= (Smith)

      Chinajá, 4; 10 km. NNW of Chinajá, 1.

All specimens were found in February and March. Those from Chinajá were
obtained from _Xanthosoma_ and bromeliads; the individual from 10
kilometers north-northwest of Chinajá is an adult male that was calling
from a puddle in a fallen tree on March 13. A juvenile having a
snout-vent length of 34.7 mm. lacks the pale blue spots on the thighs;
instead, the anterior and posterior surfaces of the thighs are bright
red.


=Hypopachus cuneus nigroreticulatus= Taylor

      Toocog, 1.

An adult male having a snout-vent length of 41.7 mm. was found at night
on the forest floor at the edge of a temporary pond. In life the dorsum
was dark brown with chocolate brown markings; the stripe on the side of
the head was white; the middorsal stripe was pale orange; the belly was
black and white, and the iris was a bronze color.

Characteristically this species inhabits savannas and open forest; thus,
its occurrence in the rainforest at Toocog is surprising. This is the
southernmost record for the species in El Petén; to the south in the
highlands it is replaced by the smaller _Hypopachus inguinalis_, having
rounded, instead of compressed, metatarsal tubercles.


=Rana palmipes= Spix

      Chinajá, 11; 15 km. NW of Chinajá, 1; 20 km. NNW of Chinajá,
      1.

With the exception of one recently metamorphosed juvenile having a
snout-vent length of 30.7 mm. that was found on the forest floor by day
on June 24, and one that was found beside a pool in a cave, all
individuals were found at temporary woodland pools or along sluggish
streams at night. The largest specimen is a female having a snout-vent
length of 107 mm.


=Rana pipiens= Schreber

      Chinajá, 1; 20 km. NNW of Chinajá, 1; Río San Román, 1;
      Toocog, 1.

All specimens were found near water at night. The largest individual is
a female having a snout-vent length of 112.5 mm.


=Crocodylus moreleti= Duméril and Duméril

      Chinajá, 1; Río San Román, 1.

One specimen was obtained from a quiet pool in the Río San Román at
night; another was found in a small sluggish stream at Chinajá. Two
large individuals were seen in tributaries to the Río San Román. On the
savannas at Toocog two small individuals were obtained in the dry
season, at which time the crocodiles apparently were migrating to water.
The local name for this species is _lagarto_.


=Chelydra rossignoni= (Bocourt)

      Chinajá, 1; 20 km. NNW of Chinajá, 1.

The paucity of specimens of _Chelydra_ from Central America has resulted
in rather inadequate diagnoses of various populations. The present
specimens have carapace lengths of 250 and 238 mm. and plastral lengths
of 185 and 176 mm. The length of carapace/bridge ratio is 6.0 and 6.1
per cent. Each individual has four barbels, the median pair of which are
extremely long. In KU 55977 the lateral pair of barbels is forked at the
base. The relative length of the plastral bridge in these specimens
compares favorable with the ratio (.06-.08) given by Schmidt (1946:4)
for five specimens from Honduras. _Chelydra serpentina_, which may occur
sympatrically with _C. rossignoni_ in some parts of Central America, has
a narrower plastral bridge and only two barbels beneath the chin.
Furthermore, _C. rossignoni_ and _C. osceola_ in Florida have long, flat
tubercles on the dorsal and lateral surfaces of the neck, whereas _C.
serpentina_ has short, round tubercles.

The specimen from Chinajá was found in a small sluggish stream; the
other individual was in a muddy pool in the forest. The local name is
_sambodanga_.


=Claudius angustatus= Cope

      20 km. NNW of Chinajá, 1.

One specimen was unearthed from the bank of a small muddy stream by a
bulldozer. This individual represents the second record for the species
in Guatemala; the first was provided by specimens, likewise found in
muddy waters, at Tikal (Stuart, 1958:19). The local name is _caiman_.


=Kinosternon acutum= Gray

      20 km. NNW of Chinajá, 4; 30 km. NNW of Chinajá, 2.

These turtles were found on the forest floor, in small sluggish streams,
and in pools in the forest. One adult male had, in life, the top of the
head yellow with black spots; the stripes on the head and neck were red.
Specimens were obtained both in the dry and rainy seasons. The local
name for both species of _Kinosternon_ is _pochitoque_.


=Kinosternon leucostomum= Duméril and Bibron

      Chinajá, 3; 15 km. NW of Chinajá, 1; 20 km. NNW of Chinajá, 2.

Individuals of this turtle were found on the forest floor and in small
sluggish streams. In life most specimens had a tan or pale brown head
with pinkish tan stripes on the head and neck. All individuals were
obtained in February and March. No ecological differences between this
species and _K. acutum_ were evident.


=Staurotypus triporcatus= (Wiegmann)

      Paso Subín, 1.

This species is represented in the collection by one complete shell
found on the bank of the Río Subín. The carapace has a length of 292 mm.
The local name is _Guao_. Natives stated that this turtle was not
uncommon in clear rivers and lakes, a habitat suggested for the species
by Stuart (1958:19).


=Dermatemys mawi= Gray

      Chinajá, 1; Río San Román, 4.

The record from Chinajá is based on a carapace found in a chiclero camp,
where the turtle evidently had been brought for food. The four specimens
from the Río San Román were obtained from edges of deep pools in clear
water. In adult males the top of the head was reddish orange in life.
One of the specimens from the Río San Román currently is living in the
Philadelphia Zoological Gardens. The local name for this turtle is
_tortuga blanca_; it is sought for its meat.


=Geoemyda areolata= (Duméril and Bibron)

      Chinajá, 2.

Two specimens were obtained from dense forest at Chinajá. The local name
is _mojina_.


=Pseudemys scripta ornata= (Gray)

      Paso Subín, 1.

One subadult was obtained from clear water in the Río Subín. The stripes
on the head and neck were yellow; there was no red "ear" on the side of
the head. The stripes on the forelimbs were orange, and the ocelli on
the carapace were red. The local name is _jicotea_.


=Coleonyx elegans elegans= Gray

      Toocog, 1.

One adult male having a snout-vent length of 89 mm. was found beneath a
log in the forest. Locally this gecko is known as _escorpión_; the
natives believe it to be deadly poisonous. The use of the name
_escorpión_ seems to be restricted to lizards thought to be venomous.
Nearly everywhere in México and Central America some species of lizard
carries this appellation. In El Petén I heard the name used only for
_Coleonyx elegans_ and _Thecadactylus rapicaudus_; in the lowlands of
Guerrero, México, the name is applied to geckos of the genus
_Phyllodactylus_. The venomous lizards of the genus _Heloderma_ in the
lowlands of western México are called _escorpiónes_. In the mountains of
southern México various skinks of the genus _Eumeces_, as well as
lizards of the genus _Xenosaurus_, carry the same appellation. _Abronia_
in the mountains of México and _Gerrhonontus_ throughout México and
Central America likewise are called _escorpiónes_. Although many people
in various parts of Middle America consider most lizards poisonous,
there is a unanimity of opinion concerning the venomous qualities of the
various kinds of _escorpiónes_. I know of only two other lizards in
Middle America that are so uniformly regarded in native beliefs; these
are _Enyaliosaurus clarki_ in the Tepalcatepec Valley in Michoacán,
called _nopiche_, and _Phrynosoma asio_ in western México, called
_cameleón_.


=Sphaerodactylus lineolatus= Lichtenstein

      15 km. NW of Chinajá, 1; Toocog, 1.

These small geckos were much more abundant than the few specimens
indicate. They frequently were seen on the trunks of corozo palms, where
they quickly took refuge in crevices at the bases of the fronds. The
specimen obtained at Toocog was under the bark of a standing dead tree.
In life the ventral surface of the tail was orange. The individual from
Chinajá was in the leaf litter on the ground at the base of a dead tree.


=Thecadactylus rapicaudus= (Houttuyn)

      15 km. NW of Chinajá, 1; 20 km. NNW of Chinajá, 2.

Two specimens were found beneath the bark of standing dead trees;
another was found in the crack in the trunk of a mahogany tree about 13
meters above the ground. In life the dorsum was yellowish tan with dark
brown markings; the venter was yellowish tan with brown flecks, and the
iris was olive-tan. The largest specimen is a male having a snout-vent
length of 95 mm.; all specimens have regenerated tails. Individuals when
caught twisted their bodies and attempted to bite; upon grabbing a
finger they held on with great tenacity.


=Anolis biporcatus= (Wiegmann)

      14 km. NNW of Chinajá, 1; 17 km. NNW of Chinajá, 1; 20 km. NNW
      of Chinajá, 3; 30 km. NNW of Chinajá, 1; Sayaxché, 1.

All specimens of this large anole were obtained from trees. Some
individuals were found in the tops of trees immediately after they were
felled. My limited observations on this anole suggest that it is an
inhabitant of the upper levels of the forest. In life an adult male from
20 kilometers north-northwest of Chinajá was brilliant green above; the
eyelids were bright yellow; the belly was white. The outer part of the
dewlap was pale orange, and the median part was pinkish blue. A juvenile
having a snout-vent length of 47 mm. and a tail length of 86 mm. was
pale grayish green with pale gray flecks on the dorsum. The largest male
has a snout-vent length of 98 mm. and a tail length of 217 mm.; the same
measurements of the largest female are 89 and 213 mm. This species,
together with all other anoles, is known locally as _toloque_.


=Anolis capito= Peters

      Chinajá, 2; 14 km. NNW of Chinajá, 1; Río de la Pasión, 1.

All individuals were observed on trunks of trees between heights of
three and ten meters above the ground. The largest male has a snout-vent
length of 81 mm. and a tail length of 155 mm.; the same measurements of
the largest female are 87 and 150 mm. The streaked brown dorsum,
combined with the lizards' habit of pressing the body against the trunks
of trees, make this anole especially difficult to see.


=Anolis humilis uniformis= Cope

      Chinajá, 24; 15 km. NW of Chinajá, 22; 20 km. NNW of Chinajá,
      6; Sayaxché, 1.

This small dull brown anole is a characteristic inhabitant of the forest
floor, where the lizards move about in a series of quick, short hops and
thus easily evade capture. Three individuals were found on small bushes,
and four were on the bases of trees; otherwise, all were observed on the
ground. Observations indicate that this species is active throughout
the day, except during and immediately after heavy rains. The males have
a deep red dewlap with a dark blue median spot.


=Anolis lemurinus bourgeaei= Bocourt

      Chinajá, 11; 20 km. NNW of Chinajá, 4; 30 km. NNW of Chinajá,
      2; Río de la Pasión, 1; Río San Román, 1; Sayaxché, 8; Toocog,
      6.

This moderate-sized anole characteristically inhabits the low bushes and
bases of trees in the forest. Individuals were most readily observed on
the buttresses of some of the gigantic mahogany and ceiba trees. When
approached the lizards usually ran around the tree or ducked to the
other side of the buttress; if the observer moved closer, they jumped to
the ground and ran off. None was observed to ascend large trees. Some
individuals were observed foraging on the forest floor; these took
shelter on the bases of trees. One individual was sleeping on a palm
frond at night. The adult males have a uniformly orange-red dewlap.


=Anolis limifrons rodriguezi= Bocourt

      15 km. NW of Chinajá, 2; 20 km. NNW of Chinajá, 1.

In dry forests and more open situations than occur at Chinajá this
little anole is abundant, but in the wet forests of southern El Petén,
only three specimens were found. Two were on palm fronds about two
meters above the ground; the other was on a low bush. I suspect that
ecologically this species overlaps _A. humilis uniformis_ and _A.
lemurinus bourgeaei_, but too few observations are recorded to justify a
definite statement at this time.


=Anolis sericeus sericeus= Hallowell

      Chinajá, 2; Sayaxché, 1; Toocog, 1.

This small anole is common and widespread in the Atlantic lowlands of
southern México and northern Central America; usually it inhabits
sub-humid regions. Consequently, its presence in the wet forests of
southern El Petén was unexpected. The specimens from Chinajá were
sleeping on low bushes at night, whereas the others were found on bushes
by day.


=Basiliscus vittatus= Wiegmann

      Chinajá, 6; Río de la Pasión, 1; Río San Román, 1; Sayaxché,
      3; Toocog, 1.

Individuals of this abundant species were most frequently seen in dense
bushes along the margins of rivers or small streams. None was observed
far from water. These lizards, like the anoles, are known locally as
_toloque_.


=Corythophanes cristatus= (Merrem)

      Chinajá, 3; 20 km. NNW of Chinajá, 1.

Three individuals were found on tree trunks; the fourth was on a thick
vine about one meter above the ground. The two largest males have
snout-vent lengths of 121 and 115 mm. and tail lengths of 265 and 243
mm. The largest female (KU 59603), obtained on June 28, has a snout-vent
length of 125 mm. and a tail length of 247 mm. This individual contained
eight ova varying in greatest diameter from 10.6 to 12.2 (average 11.1)
mm. Also present are numerous ovarian eggs having diameters up to about
3.5 mm.

One of the large males displayed a defensive behavior prior to capture.
When first observed the lizard was clinging to a tree trunk about one
and one-half meters above the ground. When I approached, the lizard
turned its flanks towards me; then it flattened the body laterally,
extended the dewlap, opened its mouth, and made short rushing motions.
When touched it bit viciously. On the ground these lizards have a rather
awkward bipedal gait that is much slower than in _Basiliscus vittatus_.

In life an adult male (KU 55804) was reddish brown dorsally with dark
chocolate brown markings; the venter was creamy white, and the iris was
dark red. The natives call this lizard _piende jente_.


=Iguana iguana rhinolopha= Wiegmann

      Río San Román, 2.

The _iguana_, as this lizard is called locally, seems to be uncommon in
the forested areas of southern El Petén. Possibly this is due to the
fact that the flesh of this lizard is relished as food by the natives.
My two specimens were in large trees at the edge of the river.


=Laemanctus deborrei= Boulenger

      Chinajá, 1; Toocog, 5.

On June 26 a female having a snout-vent length of 129 mm. and a tail
length of 502 mm. was found on a bush in the forest. The lizard, when
approached, faced the collector and opened its mouth. In life the dorsum
was bright green; the lateral stripe was white, and the iris was
yellowish brown. This specimen contained four ova having lengths of 13.4
to 14.2 (average 13.9) mm.

On June 30 at Toocog five white-shelled eggs were found in a rotting
log. Measurements of the eggs are--length, 23.5 to 25.0 (average 24.2)
mm.; width, 15.0 to 15.5 (average 15.4) mm. These eggs hatched on August
30. The five young had snout-vent lengths of 43 to 45 (average 44) mm.,
and tail lengths of 137 to 140 (average 138) mm. In life the hatchlings
had a dull dark green dorsum, pale bright green venter and stripes on
head, and reddish brown iris. In preservative the hatchlings are creamy
tan above with five or six square dark brown blotches middorsally.

The natives consider this lizard to be one of the anoles; consequently,
it is known as _toloque_.


=Lepidophyma flavimaculatum flavimaculatum= Duméril

      Chinajá, 8; 15 km. NW of Chinajá, 2.

Individuals were found beneath logs on the forest floor or moving about
in the litter on the forest floor. One was observed crawling across a
trail during a heavy rain. In some adults the tan dorsal spots are large
and distinct; in others the spots are small and indistinct. Two
juveniles, apparently recent hatchlings, were found on June 28 and July
5. These specimens have snout-vent lengths of 29 mm. and tail lengths of
38 and 41 mm.


=Eumeces schwartzei= Fischer

      Chinajá, 1.

One specimen (KU 59551) was found on the forest floor at midday; it is
an adult female having a snout-vent length of 125 mm. and a tail length
of 210 mm. This specimen is larger than those recorded by Taylor
(1936:99) and extends the known range of the species south of Ramate,
approximately 125 kilometers south-south-westward to Chinajá.


=Eumeces sumichrasti= (Cope)

      20 km. NNW of Chinajá, 1.

One adult male having a snout-vent length of 82 mm. was found beneath a
palm frond on the forest floor. In life the dorsum was dull brown; the
chin was cream; the belly was yellow, and the underside of the tail was
orange. A juvenile having a black body, yellow dorsal stripes, and a
bright blue tail was observed on the forest floor.


=Scincella cherriei cherriei= (Cope)

      Chinajá, 2; 30 km. NNW of Chinajá, 1; Toocog, 1.

All individuals of this lizard were found in the leaf litter on the
forest floor; many escaped capture. In life the tail is dull bluish
gray. The number of dorsal scales varies from 59 to 61 (average 60);
thus, these specimens fall within the range of variation of _S. cherriei
cherriei_, and thereby differ from _S. cherriei stuarti_ to the west and
_S. cherriei ixbaac_ to the north.


=Ameiva festiva edwardsi= Bocourt

      Chinajá, 16; 15 km. NW of Chinajá, 10; Sayaché, 4; Toocog, 1.

This abundant terrestrial lizard, locally called _lagartijo_, is found
throughout the forest. A juvenile obtained on March 14 at Sayaxché has a
snout-vent length of 42 mm. and a prominent umbilical scar. Other
juveniles were observed at Chinajá in February and March, thereby
indicating that the young probably hatch in the early part of the year.
Juveniles have bright blue tails.


=Celestus rozellae= Smith

      20 km. NNW of Chinajá, 2.

Two specimens were obtained from trees by workmen in February. These
lizards have snout-vent lengths of 70 and 83 mm. and tail lengths of 133
and 135 mm. There are 21 and 23 lamellae beneath the fourth toe; each
has 31 longitudinal rows of scales around the body.


=Boa constrictor imperator= Daudin

      15 km. NW of Chinajá, 1; 20 km. NNW of Chinajá, 2; Toocog, 1.

All specimens were found on the forest floor. One individual was found
in combat with a large _Drymarchon corais melanurus_. Apparently, the
_Drymarchon_ was attempting to devour the _Boa_, which had a total
length of 1683 mm. Locally this snake is called _masacuata_; it is one
of the few snakes believed by the local inhabitants to be non-poisonous.


=Clelia clelia clelia= Daudin

      15 km. NW of Chinajá, 1; 20 km. NNW of Chinajá, 1.

One specimen is represented only by the head; the snake was killed on
the forest floor by workmen. Another individual was found in a pool of
water at the base of a limestone outcropping in the forest; this
specimen (KU 58167) is a female having a body length of 2220 mm. and a
total length of 2634 mm. This snake contained 22 ova averaging 56 × 23
mm. Both specimens were uniform shiny black above and cream-color below.
The local name is _sumbadora_.


=Coniophanes bipunctatus bipunctatus= (Günther)

      Chinajá, 1.

This snake was found on the forest floor by day; it is a male having 130
ventrals, an incomplete tail; cream-colored belly, and a pair of large
brown spots on each ventral scute.


=Coniophanes fissidens fissidens= (Günther)

      Toocog, 1.

This male specimen was found beneath a rock in a sink hole. It has 122
ventrals and 77 caudals. A narrow temporal stripe extends along the
upper edge of the anterior temporal and the lower edge of the upper
secondary temporal. The belly is ashy white with a pair of small black
spots on each ventral.


=Coniophanes imperialis clavatus= (Peters)

      Chinajá, 3.

All specimens were found on the forest floor by day. These small snakes
are capable of rapid movement and quickly disappear in the litter on the
ground. Two individuals evaded capture. The belly is creamy white
anteriorly and vermillion red posteriorly.


=Dryadophis melanolomus laevis= (Fischer)

      Chinajá, 3.

These snakes, locally known as _sumbadora_, were found on the forest
floor; two others were seen, but escaped. The variation in coloration
has been a source of confusion in this species in northern Central
America (see Stuart, 1941:86). All of the present specimens are males:
KU 55709 has 178 ventrals, 121 caudals, and a total length of 914 mm.;
the dorsum is olive-tan with six darker cross-bars on the neck; the
belly is creamy white. KU 58160 has 188 ventrals, 123 caudals, and a
total length of 1365 mm.; the dorsum is uniform olive-brown, except that
some dorsal scales at midbody have black anterior borders like _D.
melanolomus melanolomus_ has in the Yucatán Peninsula; the venter is
pale yellow. KU 58158 has 179 ventrals, 122 caudals, and a total length
of 723 mm.; the dorsum is rich chocolate brown with eight dark
cross-bars on the neck; the belly is bright orange.

Stuart (1941a:87) stated that in life two distinct color phases were
observed in specimens collected by him in Alta Verapaz, Guatemala. One
had an olive-brown dorsum and the other, a reddish orange dorsum.
Stuart made no mention of variation in the color of the venter. Similar
variation is known in _D. melanolomus alternatus_ in Costa Rica, where
some individuals have orange-red venters. This color phase has been
recognized as a distinct species, _Dryadophis sanguiventris_, by Taylor
(1954:722). Examination of 18 specimens from Costa Rica shows no
differences in scutellation, nor geographic segregation of two
populations. I am convinced that the red-bellied _Dryadophis_ in Costa
Rica, like those in Guatemala, represent a color phase of the subspecies
inhabiting those areas and that _Dryadophis sanguiventris_ Taylor is a
synonym of _Dryadophis melanolomus alternatus_ (Bocourt).


=Drymarchon corais melanurus= (Duméril, Bibron and Duméril)

      15 km. NW of Chinajá, 1; Sayaxché, 1.

The specimen from Sayaxché was found at the edge of a clearing in the
forest; that from 15 kilometers northwest of Chinajá was found on the
forest floor coiled with a _Boa constrictor imperator_, which the
_Drymarchon_ apparently was trying to eat. The _Drymarchon_ is a giant
specimen having a total length of 2950 mm. (see Duellman, 1961:368). The
_Boa_ with which it was coiled has a total length of 1683 mm. I was
attracted to the snakes by a loud thrashing noise. When I approached the
writhing mass, the snakes separated, but I was able to see that the
_Drymarchon_ had its teeth firmly imbedded in the posterior part of the
head of the _Boa_. From the _Drymarchon_ I forced the regurgitation of a
recently ingested _Bothrops nummifer nummifer_ having a total length of
953 mm. These observations show that the snake-eating capabilities of
_Drymarchon_ can hardly be over-estimated.

In both _Drymarchon_ the anterior one-half of the body is olive-tan,
which changes to bluish black posteriorly. The local name is
_sumbadora_.


=Drymobius margaritiferus margaritiferus= (Schlegel)

      Chinajá, 3; Sayaxché, 1.

All individuals were obtained in clearings in the forest by day in the
rainy season. Two individuals each contained a _Similisca baudini_ and
another contained a _Bufo valliceps valliceps_. Locally this snake is
known by the appropriate name of _ranera_.


=Imantodes cenchoa leucomelas= Cope

      Chinajá, 4.

With the exception of one that was found dead in camp, all individuals
were taken from low vegetation by day. The dorsum is creamy tan with 28
to 35 (average 32) chocolate brown blotches, and the venter is ashy
white with small brown flecks. Three males have 238 to 248 (average 244)
ventrals and 148 to 154 (average 151) caudals; one female has 239
ventrals and 142 caudals. The largest specimen, a male, has a body
length of 660 mm. and a total length of 943 mm.


=Lampropeltis doliata polyzona= Cope

      Chinajá, 1.

One female (KU 57156) having 230 ventrals and 54 caudals was found on
the forest floor by day. This individual has a black snout with a white
bar across the nasals and prefrontals, a white spot in the middle of the
frontal, and a white band across the temporals and parietals that is
bordered posteriorly by a black band. There are 28 white and 28 red
rings on the body. The tips of the red scales are darkened. The black
rings between the white and red rings are not so expanded as to
interrupt the white rings dorsally as in _L. doliata abnorma_ as
identified by Stuart (1948:70). Locally this snake, like all red, black,
and white or yellow banded snakes, is called _coral_ or _coralillo_.


=Leptodeira frenata malleisi= Dunn and Stuart

      Toocog, 1.

This specimen, a male having 173 ventrals and 69 caudals, was found
beneath the bark on a log in the forest. In life the dorsum was pinkish
tan with 36 chocolate brown blotches on the body; the venter was rosy
pink.


=Leptodeira septentrionalis polysticta= Günther

      Chinajá, 3; Toocog, 11.

If numbers of specimens are indicative of abundance, this is the most
common snake in southern El Petén. All were found at night in the rainy
season. At a pond in the forest at Toocog these snakes were observed on
low vegetation, on the ground, and in the water. Evidently they
congregate at breeding choruses of frogs. One _Leptodeira_ contained a
_Smilisca baudini_ and another contained eggs of _Phyllomedusa
callidryas taylori_. The natives call this snake _nahuyaca_.


=Leptophis ahaetulla praestans= (Cope)

      13 km. NNW of Chinajá, 1; 20 km. NNW of Chinajá, 1.

Both specimens were obtained from trees when they were felled. One
individual (KU 55716) has a body length of 1345 mm. and a total length
of 2035 mm. In life the entire snake was uniform bright green; the eye
was yellow. In preservative the dorsum is dark blue, and the venter is
green.


=Leptophis mexicanus mexicanus= Duméril, Bibron and Duméril

      Chinajá, 1; 15 km. NW of Chinajá, 1; Sayaxché, 4.

All specimens came from low trees in the forest. The largest specimen is
a male having a body length of 724 mm. and a total length of 1236 mm. In
life the middorsum was a golden tan; the top of the head was a vivid
green. One individual had ingested a _Smilisca baudini_. The local name
is _bejuquillo_.


=Ninia sebae sebae= (Duméril, Bibron and Duméril)

      Toocog, 1.

This specimen, a male having 144 ventrals and 55 caudals, was found
beneath bark on a log in the forest. There is a black band five scales
in length on the nape followed posteriorly by a red band six scales in
length and then by a complete black band one and one-half scales in
length. The rest of the body is dull red with 16 incomplete black bands
one to one and one-half scales in length on the anterior two-thirds of
the body.


=Oxybelis aeneus aeneus= (Wagler)

      Chinajá, 1; 20 km. NNW of Chinajá, 1.

One individual was found in a low tree; the other was in a bush. Both
specimens are males; the largest has a body length of 754 mm. and a
total length of 1286 mm. Bogert and Oliver (1945:388) distinguished _O.
aeneus aeneus_ in Central and South America from _O. aeneus auratus_ in
México in that the diameter of the eye is more than the length of the
internasal, whereas in _O. aeneus auratus_ the diameter of the eye is
less than the length of the internasal. Stuart (1958:27) stated that on
the basis of this character three specimens from Tikal in northeastern
El Petén definitely were _O. aeneus aeneus_. Of the present specimens
from southern El Petén, one has an internasal:eye ratio of 1.08; the
other has a ratio of 0.87. A careful review of these snakes is needed to
verify the validity of the characters used to separate the subspecies
and to determine areas of intergradation. The local name for the
vine-snake is _bejuquillo_.


=Pliocercus euryzonus aequalis= Salvin

      Chinajá, 1; Río San Román, 1.

These specimens are tentatively referred to _P. euryzonus_. KU 57160 is
a female having 130 ventrals, 87 caudals, and 23 black rings on the
body; KU 58150 is a juvenile having 128 ventrals, 79 caudals, and 27
black rings on the body. In both specimens the tip of the snout is
yellow; a broad yellow band on the parietals and temporals is bordered
posteriorly by a black band on the nape. The black rings on the body are
not bordered by yellow, but black rings on the tail have yellow borders
ventrally. In the red interspaces between the black rings, black flecks
and spots, especially posteriorly, tend to form secondary black rings
(Fig. 6a). According to Stuart (1948:71), _P. euryzonus aequalis_ has 25
to 27 black rings on the body, whereas _P. elapoides salvini_, which
also occurs in El Petén, has 15 to 23 black rings.

[Illustration: FIG. 6. Dorsal color patterns of _Pliocercus euryzonus
aequalis_ (A) and _Micrurus affinis apiatus_ (B).]

The specimen from the Río San Román contained a partly digested
_Bolitoglossa moreleti mulleri_. Locally _Piocercus_ is called _coral_
or _coralillo_.


=Pseustes poecilonotus poecilonotus= (Günther)

      Chinajá, 3; 20 km. NNW of Chinajá, 1.

Two juveniles were on the forest floor; one juvenile and an adult were
on low bushes. The juveniles have a tan dorsum with reddish brown
blotches; the belly is gray, and the iris is cream-color above and brown
below. The one adult is olive-brown above and creamy white below on the
anterior three-fourths of the body; posteriorly it is black above and
below. There are no paravertebral dark stripes nor pale spots on the
dorsal scales.

Two specimens (one juvenile and the adult) when encountered compressed
the anterior part of the body laterally and struck repeatedly. Locally
the adults are called _sumbadora_.


=Sibon dimidiata dimidiata= (Günther)

      20 km. NNW of Chinajá, 2.

Both snakes were obtained from trees when they were felled. In life the
dorsum was pinkish orange with dark chocolate brown blotches narrowly
edged with black.


=Sibon nebulata nebulata= (Linnaeus)

      20 km. NW of Chinajá, 1.

This specimen, a male having a body length of 544 mm. and a tail length
of 198 mm., was found in a felled tree. In life the belly was pink and
black; the dorsal black blotches were narrowly outlined with pink.


=Spilotes pullatus mexicanus= (Laurenti)

      Chinajá, 3; 20 km. NNW of Chinajá, 1; Sayaxché, 1.

This large snake, locally called _mica_, seems to be equally at home on
the ground and in low trees and bushes. It is fast moving for a large
snake; two individuals escaped capture. The natives said that this snake
eats other snakes, but examination of stomachs revealed no supporting
evidence.


=Stenorrhina degenhardti= (Berthold)

      Chinajá, 1.

This specimen, a female having 158 ventrals, 37 caudals, and a total
length of 489 mm., was found on the forest floor. On the olive-brown
dorsum are 27 irregular, narrow, dark brown, transverse bands. The head
is uniform olive-brown; the chin and labials are cream-color. The
venter is cream-color with a row of brown spots forming a midventral
stripe. A large spider was found in the stomach.

I have refrained from assigning a subspecific name to this snake.
Cursory examination of specimens from throughout México and Central
America reveals a bewildering array of variation in coloration that
suggests that the subspecies _mexicanus_ is not recognizable, or that
two species occur sympatrically in parts of southern México and northern
Central America.


=Tretanorhinus nigroluteus lateralis= Bocourt

      Chinajá, 1.

A single male having 136 ventrals, 75 caudals, and a total length of 407
mm. was found by a stream in camp. The dorsum is pale grayish tan with
34 pairs of small chocolate brown spots, some of the anterior ones of
which are connected across the back. A cream-colored lateral stripe is
on the third and fourth dorsal scale-rows anteriorly and the second and
third rows posteriorly. The lower dorsal scale rows are black. The
venter is dark grayish brown with cream-colored flecks anteriorly and
creamy gray posteriorly where the dark color is restricted to the
midventral region and the lateral edges of ventrals and first dorsal
scale-row.


=Xenodon rabdocephalus mexicanus= Smith

      Chinajá, 1; 20 km. NNW of Chinajá, 1.

Both individuals were found on the forest floor. An adult male having a
total length of 420 mm. has a cream-colored venter with brown flecks. A
juvenile having a total length of 172 mm. has a creamy white belly with
black crossbands.

At the suggestion of L. C. Stuart, I am following Schmidt (1941:501) in
placing _X. mexicanus_ as a subspecies of _X. rabdocephalus_.


=Micrurus affinis apiatus= (Jan)

      20 km. NNW of Chinajá, 2; Sayaxché, 1.

All specimens were found beneath litter on the forest floor. All are
males having 202 to 211 (average 205) ventrals, 53 to 56 (54.6) caudals,
and 34 to 48 (41) primary black rings on the body. There are no yellow
rings, and black spots in the red interspaces tend to form secondary
black rings (Fig. 6b), the same as in _Pliocercus euryzonus aequalis_.
The local name is _coral_ or _coralillo_.


=Bothrops atrox asper= (Garman)

      15 km. NW of Chinajá, 1; Sayaxché, 1.

Although we found only two specimens, natives and workmen at the camp at
Chinajá stated that the _barba amarilla_, as this snake is known
locally, had been abundant when the camp had been established less than
two years before our visit.


=Bothrops nasutus= Bocourt

      12 km. NW of Chinajá, 1.

This specimen, a male having a total length of 415 mm., was found on the
forest floor. The dorsum is brown with dark brown blotches separated
middorsally by a narrow orange-tan stripe extending from the nape to the
base of the tail. The belly is grayish tan with white flecks on the
lateral edges of the ventrals. The local name is _nahuyaca_.


=Bothrops nummifer nummifer= (Rüppell)

      15 km. NW of Chinajá, 2; Sayaxché, 1.

Two individuals were found on the forest floor, and one adult, having a
total length of 953 mm., was removed from the stomach of a large
_Drymarchon corais melanurus_. There is considerable variation in color
and pattern. A juvenile (KU 58104), having a total length of 332 mm.,
has a tan dorsum with 19 interconnected dark brown, diamond-shaped,
middorsal blotches, the lateral extensions of which are black; the belly
is a cream-color with brown squares. An adult female (KU 55706), having
a total length of 779 mm., has a dorsal coloration like the preceding
specimen, except that the lateral extensions of the dorsal blotches are
brown; the belly is a uniform cream-color. A second adult female (KU
55707), having a total length of 953 mm., has a brown dorsum with 21
interconnected black, diamond-shaped, middorsal blotches, the lateral
extensions of which are black; the belly is a cream-color with black
squares.

The local name for this species is _braza de piedra_.


=Bothrops schlegeli schlegeli= (Berthold)

      Paso Subín, 1.

This specimen was taken from the thatched roof of a house at the edge of
the forest and contained the remains of a small mammal. The local name
is _nahuyaca_.




HYPOTHETICAL LIST OF SPECIES


Listed below are thirteen species that have not been found in southern
El Petén but that probably occur there.

      =_Dermophis mexicanus mexicanus_= (Duméril and Bibron).--Natives
      at Chinajá know caecilians, which they call _dos cabezas_.
      This species has been taken in Tabasco and northern Chiapas.
      Its occurrence in southern El Petén is expected. Less likely,
      the caecilian known to the natives at Chinajá is _Gymnopis
      oligozona_, which is known from Finca Volcán on the southern
      slopes of the valley of the Río Cahabón in Alta Verapaz.

      =_Gastrophryne elegans_= (Boulenger).--This small fossorial frog
      is known from Piedras Negras (Taylor and Smith, 1945:604), 12
      miles east of Yaxha (Stuart, 1934:7), and Tikal (Stuart,
      1958:18), all in northern and central El Petén. Two specimens
      in the collection of the University of Kansas are from 28
      kilometers northeast of Campur, Alta Verapaz. Probably the
      species ranges throughout the forested lowlands of northern
      Alta Verapaz and El Petén.

      =_Mabuya brachypoda_= Taylor.--The absence of this widespread
      lizard in our collections cannot be explained. Probably it
      occurs in southern El Petén, for it is known in northern and
      central El Petén and in Alta Verapaz.

      =_Dendrophidion vinitor_= Smith.--This snake is known from
      Piedras Negras, El Petén and from various localities in Alta
      Verapaz; it is an inhabitant of humid forest and should occur
      in southern El Petén.

      =_Elaphe triaspis mutabilis_= (Cope).--The subspecies _E.
      triaspis mutabilis_ is known from Alta Verapaz and _E.
      triaspis triaspis_ from the Yucatán Peninsula, British
      Honduras, and Uaxactún in northern El Petén. Because of the
      much higher degree of resemblance between the faunas of
      southern El Petén and Alta Verapaz as compared with southern
      El Petén and Yucatán, _E. triaspis mutabilis_ would be
      expected to occur in southern El Petén.

      =_Ninia diademata nietoi_= Burger and Werler.--This snake is
      known from Tikal and from Alta Verapaz; it is a small
      cryptophile that probably occurs in southern El Petén.

      =_Oxyrhophus petola aequifasciatus_= Werner.--This snake, which
      probably is conspecific with _Oxyrhophus baileyi_ in southern
      Veracruz, México, is known from Tikal, British Honduras, and
      Alta Verapaz; it is expected in southern El Petén.

      =_Pliocercus elapoides salvini_= Müller.--This species is
      widespread in the Atlantic lowlands of southern México and
      northern Central America; the subspecies _P. elapoides
      salvini_ occurs in Alta Verapaz and probably in southern El
      Petén.

      =_Rhadinaea decorata decorata_= (Günther).--This is another
      small cryptophile that is widespread on the Atlantic lowlands
      from México to Panamá; it definitely is expected at places
      like Chinajá in southern El Petén.

      =_Scaphiodontophis annulatus_= (Duméril and Bibron).--Three
      subspecies of _Scaphiodontophis annulatus_ are recognized in
      northern Central America: _S. annulatus annulatus_ from Alta
      Verapaz, _S. annulatus hondurensis_ from northern Honduras,
      and _S. annulatus carpicinctus_ from Piedras Negras and Tikal
      in El Petén and from British Honduras. This rare and highly
      variable species probably occurs in southern El Petén.

      =_Tantilla schistosa schistosa_= (Bocourt).--This widespread
      species in Central America is known from several localities in
      Alta Verapaz and almost certainly occurs in southern El Petén.

      =_Tropidodipsas sartori sartori_= Cope.--This fossorial species
      has been collected in northern El Petén and in Alta Verapaz.
      The natives at Chinajá described to me a _coral_ having orange
      rings on a black body that likely was this species.

      =_Micrurus elegans veraepacis_= Schmidt.--This species has been
      collected at various localities in Alta Verapaz and in
      Chiapas, inhabits areas like those in southern El Petén, and
      probably occurs there.




SUMMARY


A study of the amphibians and reptiles in the rainforests of southern El
Petén, Guatemala, reveals the presence of 78 species; an additional 13
species probably occur there. In this tropical area having a high amount
of rainfall most of the species of amphibians and reptiles have
extensive ranges in the wet forests on the Atlantic lowlands of southern
México and northern Central America; some species that more frequently
are found in sub-humid forests also occur.

Ecologically the fauna is divided into five major habitats--aquatic,
aquatic margin, fossorial, terrestrial, and arboreal. Forty-two per cent
of the 78 species are wholly or partly arboreal. The fauna is most
closely related to that in Alta Verapaz, Guatemala, but includes many
species that occur in the Tikal-Uaxactún area in northeastern Guatemala.

_Eleutherodactylus rostralis_ (Werner) and _E. rhodopis_ (Cope) are
redefined and their relationships are suggested. The color phases of
_Dryadophis melanolomus laevis_ and _D. m. alternatus_ are discussed;
_Dryadophis sanguiventris_ Taylor is synonymized with _Dryadophis
melanolomus alternatus_ (Bocourt).

The breeding habits, eggs, and tadpoles of the hylid frogs _Hyla
ebraccata_ and _Phyllomedusa callidryas taylori_ are described, as are
the eggs and juveniles of _Laemanctus deborrei_.




LITERATURE CITED


BAYLOR, E. R. AND STUART, L. C.

      1961. A new race of _Bufo valliceps_ from Guatemala. Proc.
      Biol. Soc. Washington, 74:195-202, August 11.

BOGERT, C. M. AND OLIVER, J. A.

      1945. A preliminary analysis of the herpetofauna of Sonora.
      Bull. Amer. Mus. Nat. Hist., 83:297-426, March 30.

BROCCHI, P.

      1881-1883 Étude des batraciens de l'Amerique Centrale. Mission
      scientifique au Mexique. Paris, Imprimerie Nationale, 3
      (2):1-122, pls. 1-21.

DUELLMAN, W. E.

      1958. A review of the frogs of the genus _Syrrhophus_ in
      western Mexico. Occas. Papers Mus. Zool. Univ. Michigan,
      594:1-15, pls. 1-3, June 6.

      1960. A distributional study of the amphibians of the Isthmus
      of Tehuantepec, México. Univ. Kansas Publ. Mus. Nat. Hist.,
      13:21-72, August 16.

      1961. A record size for _Drymarchon corais melanurus_. Copeia,
      1960 (4):367-368, January.

DUNN, E. R. AND EMLEN, J. T.

      1932. Reptiles and amphibians from Honduras. Proc. Acad. Nat.
      Sci. Philadelphia, 84:21-32, March 22.

FIRSCHEIN, I. L. AND SMITH, H. M.

      1957. A high-crested race of toad (_Bufo valliceps_) and other
      noteworthy reptiles and amphibians from southern Mexico.
      Herpetologica, 13:219-222, October 31.

LUNDELL, C. L.

      1937. The vegetation of Petén. Carnegie Institute Washington
      Publ. 178:1-244, pls. 1-39. June 16.

NEILL, W. T. AND ALLEN, R.

      1959. Studies on the amphibians and reptiles of British
      Honduras. Publ. Ross Allen's Reptile Inst., 2:1-76, November
      10.

SAPPER, K.

      1932. Klimakunde von Mittelamerika. _In_ Handbuch Klimakunde,
      2:1-74, Taf. 1-13.

SCHMIDT, K. P.

      1936. Guatemalan salamanders of the genus _Oedipus_. Zool.
      Ser. Field Mus. Nat. Hist., 20:135-166, October 31.

      1941. The amphibians and reptiles of British Honduras. Zool.
      Ser. Field Mus. Nat. Hist, 22:475-510, December 30.

      1946. Turtles collected by the Smithsonian Biological Survey
      of the Panamá Canal Zone. Smithsonian Misc. Coll., 106
      (8):1-9, pl. 1, August 1.

SIMPSON, G. G.

      1960. Notes on the measurement of faunal resemblance. Amer.
      Jour. Sci., 258-A:300-311.

SMITH, H. M. AND TAYLOR, E. H.

      1945. An annotated checklist and key to the snakes of Mexico.
      Bull. U. S. Natl. Mus., 187: iv + 239 pp., October 5.

      1948. An annotated checklist and key to the amphibia of
      Mexico. Bull. U. S. Natl. Mus., 194: iv + 118 pp., June 17.

      1950. An annotated checklist and key to the reptiles of Mexico
      exclusive of the snakes. Bull. U. S. Natl. Mus., 199: v + 253
      pp., October 26.

STUART, L. C.

      1934. A contribution to a knowledge of the herpetological
      fauna of El Peten, Guatemala. Occas. Papers Mus. Zool. Univ.
      Michigan, 292:1-18, June 29.

      1935. A contribution to a knowledge of the herpetology of a
      portion of the savanna region of central Petén, Guatemala.
      Misc. Publ. Mus. Zool. Univ. Michigan, 29:1-56, pls. 1-4,
      October 1.

      1937. Some further notes on the amphibians and reptiles of the
      Peten forest of northern Guatemala. Copeia, 1937 (1):67-70,
      April 10.

      1941a. Studies of Neotropical Colubrinae VIII. A revision of
      the genus _Dryadophis_ Stuart, 1939. Misc. Publ. Mus. Zool.
      Univ. Michigan, 49:1-105, pls. 1-4, March 19.

      1941b. Two new species of _Eleutherodactylus_ from Guatemala.
      Proc. Biol. Soc. Washington, 54:197-200, December 8.

      1943. Taxonomic and geographic comments on Guatemalan
      salamanders of the genus _Oedipus_. Misc. Publ. Mus. Zool.
      Univ. Michigan, 56:1-33, pls. 1-2, January 30.

      1948. The amphibians and reptiles of Alta Verapaz, Guatemala.
      Misc. Publ. Mus. Zool. Univ. Michigan, 69:1-109, June 12.

      1950. A geographic study of the herpetofauna of Alta Verapaz,
      Guatemala. Contr. Lab. Vert. Biol. Univ. Michigan, 45:1-77,
      pls. 1-9, May.

      1958. A study of the herpetofauna of the Uaxactun-Tikal area
      of northern El Peten, Guatemala. Contr. Lab. Vert. Biol. Univ.
      Michigan, 75:1-30, June.

TAYLOR, E. H.

      1936. A taxonomic study of the cosmopolitan scincoid lizards
      of the genus _Eumeces_. Univ. Kansas Sci. Bull., 23:1-643,
      August 15.

      1954. Further studies on the serpents of Costa Rica. Univ.
      Kansas Sci. Bull., 36:673-801, July 15.

TAYLOR, E. H. AND SMITH, H. M.

      1945. Summary of collections of amphibians made in Mexico
      under the Walter Rathbone Bacon Traveling Scholarship. Proc.
      U. S. Natl. Mus., 95:521-613, June 30.

_Transmitted November 29, 1962._

29-5935




UNIVERSITY OF KANSAS PUBLICATIONS MUSEUM OF NATURAL HISTORY


Institutional libraries interested in publications exchange may obtain
this series by addressing the Exchange Librarian, University of Kansas
Library, Lawrence, Kansas. Copies for individuals, persons working in a
particular field of study, may be obtained by addressing instead the
Museum of Natural History, University of Kansas, Lawrence, Kansas. There
is no provision for sale of this series by the University Library, which
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meets the requests of individuals. However, when individuals request
copies from the Museum, 25 cents should be included, for each separate
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the costs of wrapping and mailing.

* An asterisk designates those numbers of which the Museum's supply (not
the Library's supply) is exhausted. Numbers published to date, in this
series, are as follows:

 Vol.  1. Nos. 1-26 and index. Pp. 1-638, 1946-1950.

*Vol.  2. (Complete) Mammals of Washington. By Walter W. Dalquest.
              Pp. 1-444, 140 figures in text. April 9, 1948.

 Vol. 3.  *1. The avifauna of Micronesia, its origin, evolution, and
              distribution. By Rollin H. Baker. Pp. 1-359, 16 figures
              in text. June 19, 1951.

          *2. A quantitative study of the nocturnal migration Of birds.
              By George H. Lowery, Jr. Pp. 361-472, 47 figures in text.
              June 29, 1951.

           3. Phylogeny of the waxwings and allied birds. By M. Dale
              Arvey. Pp. 473-530, 49 figures in text, 13 tables. October
              10, 1951.

          *4. Birds from the state of Veracruz, Mexico. By George H.
              Lowery, Jr., and Walter W. Dalquest. Pp. 531-649, 7
              figures in text, 2 tables. October 10, 1951.

          Index. Pp. 651-681.

*Vol.  4. (Complete) American weasels. By E. Raymond Hall. Pp. 1-466, 41
              plates, 31 figures in text. December 27, 1951.

 Vol.  5. Nos. 1-37 and index. Pp. 1-676, 1951-1953.

*Vol.  6. (Complete) Mammals of Utah, _taxonomy and distribution_. By
              Stephen D. Durrant. Pp. 1-549, 91 figures in text, 30
              tables. August 10, 1952.

 Vol.  7. Nos. 1-15 and index. Pp. 1-651, 1952-1955.

 Vol.  8. Nos. 1-10 and index. Pp. 1-675. 1954-1956.

 Vol.  9. *1. Speciation of the wandering shrew. By James S. Findley.
              Pp. 1-68, 18 figures in text. December 10, 1955.

           2. Additional records and extension of ranges of mammals from
              Utah. By Stephen D. Durrant, M. Raymond Lee, and Richard
              M. Hansen. Pp. 69-80. December 10, 1955.

           3. A new long-eared myotis (Myotis evotis) from northeastern
              Mexico. By Rollin H. Baker and Howard J. Stains. Pp.
              81-84. December 10, 1955.

           4. Subspeciation in the meadow mouse, Microtus
              pennsylvanicus, in Wyoming. By Sydney Anderson. Pp.
              85-104, 2 figures in text. May 10, 1956.

           5. The condylarth genus Ellipsodon. By Robert W. Wilson. Pp.
              105-116, 6 figures in text. May 19, 1956.

           6. Additional remains of the multituberculate genus
              Eucosmodon. By Robert W. Wilson. Pp. 117-123, 10 figures
              in text. May 19, 1956.

           7. Mammals of Coahuila, Mexico. By Rollin H. Baker. Pp.
              125-335, 75 figures in text. June 15, 1956.

           8. Comments on the taxonomic status of Apodemus peninsulae,
              with description of a new subspecies from North China. By
              J. Knox Jones, Jr. Pp. 337-346, 1 figure in text, 1 table.
              August 15, 1956.

           9. Extensions of known ranges of Mexican bats. By Sydney
              Anderson. Pp. 347-351. August 15, 1956.

          10. A new bat (Genus Leptonycteris) from Coahuila. By Howard
              J. Stains. Pp. 353-356. January 21, 1957.

          11. A new species of pocket gopher (Genus Pappogeomys) from
              Jalisco, Mexico. By Robert J. Russell. Pp. 357-361.
              January 21, 1957.

          12. Geographic variation in the pocket gopher, Thomomys
              bottae, in Colorado. By Phillip M. Youngman. Pp. 363-387,
              7 figures in text. February 21, 1958.

          13. New bog lemming (genus Synaptomys) from Nebraska. By J.
              Knox Jones, Jr. Pp. 385-388. May 12, 1958.

          14. Pleistocene bats from San Josecito Cave, Nuevo León,
              México. By J. Knox Jones, Jr. Pp. 389-396. December 19,
              1958.

          15. New subspecies of the rodent Baiomys from Central America.
              By Robert L. Packard. Pp. 397-404. December 19, 1958.

          16. Mammals of the Grand Mesa, Colorado. By Sydney Anderson.
              Pp. 405-414, 1 figure in text. May 20, 1959.

          17. Distribution, variation, and relationships of the montane
              vole, Microtus montanus. By Sydney Anderson. Pp. 415-511,
              12 figures in text, 2 tables. August 1, 1959.

          18. Conspecificity of two pocket mice, Perognathus goldmani
              and P. artus. By E. Raymond Hall and Marilyn Bailey
              Ogilvie. Pp. 513-518, 1 map. January 14, 1960.

          19. Records of harvest mice, Reithrodontomys, from Central
              America, with description of a new subspecies from
              Nicaragua. By Sydney Anderson and J. Knox Jones, Jr. Pp.
              519-529. January 14, 1960.

          20. Small carnivores from San Josecito Cave (Pleistocene),
              Nuevo León, México. By E. Raymond Hall. Pp. 531-538, 1
              figure in text. January 14, 1960.

          21. Pleistocene pocket gophers from San Josecito Cave, Nuevo
              León, México. By Robert J. Russell. Pp. 539-548, 1 figure
              in text. January 14, 1960.

          22. Review of the insectivores of Korea. By J. Knox Jones,
              Jr., and David H. Johnson. Pp. 549-578. February 23, 1960.

          23. Speciation and evolution of the pygmy mice, genus Baiomys.
              By Robert L. Packard. Pp. 579-670, 4 plates, 12 figures in
              text. June 16, 1960.

          Index. Pp. 671-690

 Vol. 10.  1. Studies of birds killed in nocturnal migration. By
              Harrison B. Tordoff and Robert M. Mengel. Pp. 1-44, 6
              figures in text, 2 tables. September 12, 1956.

           2. Comparative breeding behavior of Ammospiza caudacuta and
              A. maritima. By Glen E. Woolfenden. Pp. 45-75, 6 plates, 1
              figure. December 20, 1956.

           3. The forest habitat of the University of Kansas Natural
              History Reservation. By Henry S. Fitch and Ronald R.
              McGregor. Pp. 77-127, 2 plates, 7 figures in text, 4
              tables. December 31, 1956.

           4. Aspects of reproduction and development in the prairie
              vole (Microtus ochrogaster). By Henry S. Fitch. Pp.
              129-161, 8 figures in text, 4 tables. December 19, 1957.

           5. Birds found on the Arctic slope of northern Alaska.  By
              James W. Bee. Pp. 163-211, plates 9-10, 1 figure in text.
               March 12, 1958.

          *6. The wood rats of Colorado: distribution and ecology. By
              Robert B. Finley, Jr. Pp. 213-552, 34 plates, 8 figures
              in text, 35 tables. November 7, 1958.

           7. Home ranges and movements of the eastern cottontail in
              Kansas. By Donald W. Janes. Pp. 553-572, 4 plates, 3
              figures in text. May 4, 1959.

           8. Natural history of the salamander, Aneides hardyi. By
              Richard F. Johnston and Gerhard A. Schad. Pp. 573-585.
              October 8, 1959.

           9. A new subspecies of lizard, Cnemidophorus sacki, from
              Michoacán, México. By William E. Duellman. Pp. 587-598,
              2 figures in text. May 2, 1960.

          10. A taxonomic study of the middle-American snake, Pituophis
              deppei. By William E. Duellman. Pp. 599-610, 1 plate, 1
              figure in text. May 2, 1960.

          Index. Pp. 611-626.

 Vol. 11. Nos. 1-10 and index. Pp. 1-703, 1958-1960.

 Vol. 12.  1. Functional morphology of three bats: Sumops, Myotis,
              Macrotus. By Terry A. Vaughan. Pp. 1-153, 4 plates, 24
              figures in text. July 8, 1959.

          *2. The ancestry of modern Amphibia: a review of the evidence.
              By Theodore H. Eaton, Jr. Pp. 155-180, 10 figures in text.
              July 10, 1959.

           3. The baculum in microtine rodents. By Sydney Anderson. Pp.
              181-216, 49 figures in text. February 19, 1960.

          *4. A new order of fishlike Amphibia from the Pennsylvanian of
              Kansas. By Theodore H. Eaton, Jr., and Peggy Lou Stewart.
              Pp. 217-240, 12 figures in text. May 2, 1960.

           5. Natural history of the bell vireo. By Jon C. Barlow. Pp.
              241-296, 6 figures in text. March 7, 1962.

           6. Two new pelycosaurs from the lower Permian of Oklahoma. By
              Richard C. Fox. Pp. 297-307, 6 figures in text. May 21,
              1962.

           7. Vertebrates from the barrier island of Tamaulipas, México.
              By Robert K. Selander, Richard F. Johnston, B. J. Wilks,
              and Gerald G. Raun. Pp. 309-345, pls. 5-8. June 18, 1962.

           8. Teeth of Edestid sharks. By Theodore H. Eaton, Jr. Pp.
              347-362, 10 figures in text. October 1, 1962.

              More numbers will appear in volume 12.

 Vol. 13.  1. Five natural hybrid combinations in minnows (Cyprinidae).
              By Frank B. Cross and W. L. Minckley. Pp. 1-18. June 1,
              1960.

           2. A distributional study of the amphibians of the
              Isthmus of Tehuantepec, México. By William E. Duellman.
              Pp. 19-72, pls. 1-8, 3 figures in text. August 16, 1960.

           3. A new subspecies of the slider turtle (Pseudemys scripta)
              from Coahuila, México. By John M. Legler. Pp. 73-84, pls.
              9-12, 3 figures in text. August 16, 1960.

           4. Autecology of the copperhead. By Henry S. Fitch. Pp.
              85-288, pls. 13-20, 26 figures in text. November 30, 1960.

           5. Occurrence of the garter snake, Thamnophis sirtalis, in
              the Great Plains and Rocky Mountains. By Henry S. Fitch
              and T. Paul Maslin. Pp. 289-308, 4 figures in text.
              February 10, 1961.

           6. Fishes of the Wakarusa river in Kansas. By James E. Deacon
              and Artie L. Metcalf. Pp. 309-322, 1 figure in text.
              February 10, 1961.

           7. Geographic variation in the North American cyprinid fish,
              Hybopsis gracilis. By Leonard J. Olund and Frank B. Cross.
              Pp. 323-348, pls. 21-24, 2 figures in text. February 10,
              1961.

           8. Descriptions of two species of frogs, genus Ptychohyla;
              studies of American hylid frogs, V. By William E.
              Duellman. Pp. 349-357, pl. 25, 2 figures in text. April
              27, 1961.

           9. Fish populations, following a drought, in the Neosho and
              Marais des Cygnes rivers of Kansas. By James Everett
              Deacon. Pp. 359-427, pls. 26-30, 3 figs. August 11, 1961.

          10. Recent soft-shelled turtles of North America (family
              Trionychidae). By Robert G. Webb. Pp. 429-611, pls. 31-54,
              24 figures in text. February 16, 1962.

          Index. Pp. 613-624.

 Vol. 14.  1. Neotropical bats from western México. By Sydney Anderson.
              Pp. 1-8. October 24, 1960.

           2. Geographic variation in the harvest mouse. Reithrodontomys
              megalotis, on the central Great Plains and in adjacent
              regions. By J. Knox Jones, Jr., and B. Mursaloglu. Pp.
              9-27, 1 figure in text. July 24, 1961.

           3. Mammals of Mesa Verde National Park, Colorado. By Sydney
              Anderson. Pp. 29-67, pls. 1 and 2, 3 figures in text. July
              24, 1961.

           4. A new subspecies of the black myotis (bat) from eastern
              Mexico. By E. Raymond Hall and Ticul Alvarez. Pp. 69-72,
              1 figure in text. December 29, 1961.

           5. North American yellow bats, "Dasypterus," and a list of
              the named kinds of the genus Lasiurus Gray. By E. Raymond
              Hall and J. Knox Jones, Jr. Pp. 73-98, 4 figures in text.
              December 29, 1961.

           6. Natural history of the brush mouse (Peromyscus boylii) in
              Kansas with description of a new subspecies. By Charles A.
              Long. Pp. 99-111, 1 figure in text. December 29, 1961.

           7. Taxonomic status of some mice of the Peromyscus boylii
              group in eastern Mexico, with description of a new
              subspecies. By Ticul Alvarez. Pp. 113-120, 1 figure in
              text. December 29, 1961.

           8. A new subspecies of ground squirrel (Spermophilus
              spilosoma) from Tamaulipas, Mexico. By Ticul Alvarez. Pp.
              121-124. March 7, 1962.

           9. Taxonomic status of the free-tailed bat, Tadarida
              yucatanica Miller. By J. Knox Jones, Jr., and Ticul
              Alvarez. Pp. 125-133, 1 figure in text. March 7, 1962.

          10. A new doglike carnivore, genus Cynaretus, from the
              Clarendonian Pliocene, of Texas. By E. Raymond Hall and
              Walter W. Dalquest. Pp. 135-138, 2 figures in text. April
              30, 1962.

          11. A new subspecies of wood rat (Neotoma) from northeastern
              Mexico. By Ticul Alvarez. Pp. 139-143. April 30, 1962.

          12. Noteworthy mammals from Sinaloa, Mexico. By J. Knox Jones,
              Jr., Ticul Alvarez, and M. Raymond Lee. Pp. 145-159, 1
              figure in text. May 18, 1962.

          13. A new bat (Myotis) from Mexico. By E. Raymond Hall. Pp.
              161-164, 1 figure in text. May 21, 1962.

          14. The mammals of Veracruz. By E. Raymond Hall and Walter W.
              Dalquest. Pp. 165-362, 2 figures. May 20, 1963.

          15. The recent mammals of Tamaulipas, México. By Ticul
              Alvarez. Pp. 363-473, 5 figures in text. May 20, 1963.

              More numbers will appear in volume 14.

 Vol. 15.  1. The amphibians and reptiles of Michoacán, México. By
              William E. Duellman. Pp. 1-148, pls. 1-6, 11 figures in
              text. December 20, 1961.

           2. Some reptiles and amphibians from Korea. By Robert G.
              Webb, J. Knox Jones, Jr., and George W. Byers. Pp.
              149-173. January 31, 1962.

           3. A new species of frog (Genus Tomodactylus) from western
              México. By Robert G. Webb, Pp. 175-181, 1 figure in text.
              March 7, 1962.

           4. Type specimens of amphibians and reptiles in the Museum
              of Natural History, the University of Kansas. By William
              E. Duellman and Barbara Berg. Pp. 183-204. October 26,
              1962.

           5. Amphibians and Reptiles of the Rainforests of Southern El
              Petén, Guatemala. By William E. Duellman. Pp. 205-249,
              pls. 7-10, 6 figures in text. October 4, 1963.

              More numbers will appear in volume 15.