Chapter I: Part 1

</pre>

Produced by Chris Curnow, Tom Cosmas, Joseph Cooper and the Online Distributed Proofreading Team at https://www.pgdp.net

UNIVERSITY OF KANSAS PUBLICATIONS
MUSEUM OF NATURAL HISTORY

Volume 15, No. 7, pp. 297-349, pls. 11-18, 7 figs.

October 18, 1963

A Review of the Middle American Tree Frogs
of the Genus Ptychohyla

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.

Volume 15, No. 7, pp. 297-349, pls. 11-18, 7 figs.

Published October 18, 1963

UNIVERSITY OF KANSAS
Lawrence, Kansas

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

[Union Label]
29-6531

A Review of the Middle American Tree Frogs
of the Genus Ptychohyla

BY
WILLIAM E. DUELLMAN

CONTENTS

PAGE

INTRODUCTION 301
Acknowledgments 301
Materials and Methods 302

ANALYSIS OF DATA 303
External Morphology 303
Color and Pattern 307
Osteology 307
Tadpoles 310
Breeding Call 312

SYSTEMATIC ACCOUNTS 314
_Ptychohyla_ Taylor, 1944 314
Key to Adults 315
Key to Tadpoles 315
_Ptychohyla euthysanota_ Group 315
_Ptychohyla euthysanota_ 315
_Ptychohyla euthysanota euthysanota_ (Kellogg) 315
_Ptychohyla euthysanota macrotympanum_ (Tanner) 320
_Ptychohyla leonhardschultzei_ (Ahl) 323
_Ptychohyla spinipollex_ (Schmidt) 327
_Ptychohyla schmidtorum_ Group 331
_Ptychohyla schmidtorum_ 331
_Ptychohyla schmidtorum schmidtorum_ Stuart 331
_Ptychohyla schmidtorum chamulae_ Duellman 334
_Ptychohyla ignicolor_ Duellman 337

DISTRIBUTION AND ECOLOGY 340
Geographic Distribution of the Species 340
Habitat Preference 342
Interspecific Competition 343
Reproduction and Development 344

PHYLOGENY OF PTYCHOHYLA 345
_Ptychohyla_ as a Natural Assemblage 345
Generic Relationships 346
Interspecific Relationships 347

LITERATURE CITED 349

INTRODUCTION

Probably no ecological group of hylid frogs (some _Hyla_ plus _Plectrohyla_ and _Ptychohyla_) in Middle America is so poorly known as those species that live in the cloud forests on steep mountain slopes and breed in cascading mountain streams. During the last half of the nineteenth century most of the species of hylids living in the lowlands of southern Mexico and northern Central America were named and described. Despite the extensive collecting by Salvin and Godman, Nelson and Goldman, and the various expeditions of the _Mission Scientifique_, no members of the genus _Ptychohyla_ were obtained until 1927, when in the mountains of El Salvador Ruben A. Stirton found a small tree frog that subsequently was described and named _Hyla euthysanota_ by Kellogg (1928). Until recently frogs of this genus were known from few specimens and in the literature by nearly as many names.

Although I first collected _Ptychohyla_ in 1956, it was not until 1960 that special efforts were made to obtain specimens of this genus. The summer of 1960 was spent in southern Mexico and Guatemala, where every accessible stream in the cloud forests was searched for tree frogs, especially _Ptychohyla_ and _Plectrohyla_. Similar, but less extensive, investigations were carried out in 1961 and 1962. The result of this field work is a rather large collection of _Ptychohyla_ representing all of the known species, plus tape recordings of the breeding calls and tadpoles of all of the species.

Previously, I have discussed the nomenclature of one of the species (Duellman, 1960) and have described two new species (Duellman, 1961). In the latter paper I made reference to a future account (this one) that would deal with the systematics and biology of the entire genus. Although I have series of specimens, tadpoles, osteological preparations, and recordings of breeding calls, thereby having a wide array of data at my disposal, much still remains to be learned about these frogs, especially about various aspects of their life histories. Even the validity of the genus is open to question; this problem is discussed at length in the section beyond entitled "_Ptychohyla_ as a Natural Assemblage."

Acknowledgments

I am indebted to the following persons for permitting me to examine specimens in their care: Miguel Alvarez del Toro, Museo Zoologia de Tuxtla Gutierrez, Mexico (MZTG); Charles M. Bogert and Richard G. Zweifel, American Museum of Natural History (AMNH); Doris M. Cochran, United States National Museum (USNM); Norman Hartweg and Charles F. Walker, University of Michigan Museum of Zoology (UMMZ); Robert F. Inger, Chicago Natural History Museum (CNHM); Hobart M. Smith, University of Illinois Museum of Natural History (UIMNH); Heinz Wermuth, Zoologisches Museum Berlin (ZMB); and Ernest E. Williams, Museum of Comparative Zoology (MCZ). The abbreviations following names of institutions will be used throughout the text; the Museum of Natural History at the University of Kansas is abbreviated KU.

Throughout my work on these frogs I have profited from discussions with L. C. Stuart, who has made many valuable suggestions and with his characteristic generosity has placed at my disposal his extensive collections of tadpoles from Guatemala. For his aid I am indeed grateful. I am grateful to Thomas E. Moore for tapes of breeding calls of two species.

My own field work was made more enjoyable and profitable through the assistance of Dale L. Hoyt, Craig E. Nelson, Jerome B. Tulecke, and John Wellman, all of whom spent many hours in often unsuccessful attempts to collect specimens and record breeding calls of _Ptychohyla_. I am indebted to many residents of Mexico, Guatemala, and El Salvador for permission to work on their land and for providing shelter, food, and guides. I am especially grateful to Mr. and Mrs. Horatio Kelly of "Colegio Linda Vista" at Pueblo Nuevo Solistahuacan, Chiapas, for a pleasant stay at their school; Jordi Julia Z. of the Comision del Papaloapan, Ciudad Aleman, Veracruz, for arranging for field work in northern Oaxaca in 1959; Walter Hannstein and Lothar Menzel for the use of facilities at Finca La Paz, Guatemala, in 1960; Alan Hempstead for the use of facilities at Finca Los Alpes, Guatemala in 1960 and 1961; and Julio Aguirre C. of the Instituto Tropical de Investigaciones Cientificas, San Salvador, El Salvador, for providing comfortable working quarters and transportation and guides to the mountains in northern El Salvador. Without the cheerful efforts of Jorge A. Ibarra, Director of the Museo Nacional de Historia Natural in Guatemala, my field work would have been greatly restricted during politically precarious times in that country. Permits to collect in Mexico were furnished by the late Luis Macias Arellano of the Direccion General de Caza. Each of these individuals has my profound thanks for his indispensable aid.

Field work on hylid frogs in Middle America has been supported by the National Science Foundation, Grant NSF-G9827, and this is the 9th publication on the results of study of the material from America.

Materials and Methods

During the course of this study I have examined 247 frogs that I assign to the genus _Ptychohyla_, plus 40 lots of tadpoles and 12 skeletal preparations. Furthermore, I have examined all of the type specimens. I have studied each of the species and subspecies in the field and have examined from seven (_P. euthysanota macrotympanum_) to 33 (_P. spinipollex_) living individuals of each species.

Measurements given in the analysis of data and in the descriptions of the species are those described by Duellman (1956). In the descriptions of living colors the capitalized names are from Ridgway (1912). All interpretations of osteological characters are based on specimens cleared in potassium hydroxide and stained with alizarin red.

Recordings of the breeding calls were made with a Magnemite Portable Tape-recorder; audiospectrographs were made on a vibralyzer (Kay Electric Company) using normal pattern and wide bandwidth.

ANALYSIS OF DATA

Data that are used to arrive at a systematic arrangement of the species of _Ptychohyla_ are analyzed and discussed below for the values inherent in the analysis. These data are of some value also in the recognition of species and subspecies but if employed for that purpose the data must be used in combination with the keys and the diagnoses of the individual species and subspecies.

External Morphology

Each of the external morphological characters used in the systematic treatment of _Ptychohyla_, as well as the nature of the tongue, is discussed below.

SIZE AND PROPORTIONS.--Comparisons of size and certain proportions are given in Table 1. Frogs of this genus are small; the largest specimen examined is a female of _P. euthysanota euthysanota_ having a snout-vent length of 53.3 mm. The species comprising the _Ptychohyla schmidtorum_ group are smaller; the largest specimen examined is a female of _P. schmidtorum schmidtorum_ having a snout-vent length of 38.0 mm. An analysis of the various measurements and proportions shows few constant differences. _Ptychohyla ignicolor_ differs from all of the other species in having the head slightly wider than long and the tympanum noticeably less than half the size of eye. _Ptychohyla spinipollex_ has a relatively narrow interorbital distance, approximately equal to the width of the eyelid, whereas in all of the other species that distance is much more than the width of the eyelid.

SNOUT.--All species have a blunt snout. In _P. leonhardschultzei_ and _P. ignicolor_ the snout is nearly square in lateral profile; in _P. schmidtorum_ the snout is slightly rounded above and below, and in the other species it is rounded above. _Ptychohyla leonhardschultzei_ and _P. spinipollex_ have a vertical fleshy rostral keel on the snout; in these species, because of this keel, the snout in dorsal profile is pointed. The nostrils are slightly protuberant in all species, and in _P. schmidtorum_ the internarial region is slightly depressed.

HAND.--The species in the _Ptychohyla euthysanota_ group have a vestige of web between the first and second fingers; the other fingers are about one-third webbed. Breeding males have a cluster of horny nuptial spines on the thumb. The spines are largest in _P. spinipollex_ (Fig. 1) and vary in number from 35 to 66 (average 47.4) on each thumb. In the other species of the _Ptychohyla euthysanota_ group the spines are smaller and usually more numerous; the numbers of spines on each thumb (means in parentheses) in members of this group are: _P. euthysanota euthysanota_, 44-143 (83.8); _P. euthysanota macrotympanum_, 40-110 (63.0); _P. leonhardschultzei_, 24-80 (54.7). The species in the _Ptychohyla schmidtorum_ group have no web between the first and second fingers and only a vestige of web between the other fingers. Furthermore, these species lack nuptial spines in breeding males. Like the usual horny excrescences on the thumbs of many species of frogs, the horny spines on the thumbs of members of the _Ptychohyla euthysanota_ group are seasonal in development.

TABLE 1.--VARIATION IN CERTAIN CHARACTERS IN THE SPECIES OF PTYCHOHYLA.
(MEANS ARE IN PARENTHESES BELOW THE RANGES.)

Key to Table Columns

A) Number of specimens
B) Maximum snout-vent length
C) Tibia length/Snout-vent length
D) Tympanum/Eye
E) Vomerine teeth

==================+========+======+=======+=========+=========+=======
Species | Sex | A | B | C | D | E
------------------+--------+------+-----------------+-----------------
| | | | | |
_P. euthysanota | [Male] | 17 | 38.1 |44.4-55.0|48.6-63.8| 4-6
euthysanota_ | | | | (48.7) | (56.3) | (5.1)
| | | | | |
|[Female]| 15 | 53.3 |46.5-56.6|42.9-56.4| 6-18
| | | | (51.4) | (51.4) | (9.6)
| | | | | |
_P. euthysanota | [Male] | 5 | 38.0 |48.8-52.0|50.0-57.1| 0-4
macrotympanum_| | | | (50.2) | (54.1) | (2.6)
| | | | | |
|[Female]| 5 | 44.8 |46.4-54.1|48.7-58.9| 8-10
| | | | (50.2) | (53.7) | (9.2)
| | | | | |
_P. leonhard | [Male] | 16 | 35.6 |48.8-56.1|48.7-61.9| 6-9
schultzei_ | | | | (51.2) | (52.1) | (6.5)
| | | | | |
|[Female]| 3 | 41.6 |52.3-59.5|47.5-48.6| 7-12
| | | | (54.7) | (48.1) | (9.5)
| | | | | |
_P. spinipollex_ | [Male] | 32 | 41.2 |46.9-53.1|45.0-55.2| 3-7
| | | | (49.0) | (49.5) | (4.9)
| | | | | |
|[Female]| 6 | 44.6 |46.1-50.2|47.7-53.8| 6-10
| | | | (48.8) | (50.4) | (7.6)
| | | | | |
_P. schmidtorum | [Male] | 25 | 32.8 |45.3-52.4|51.5-59.3| 5-11
schmidtorum_ | | | | (48.1) | (54.7) | (6.2)
| | | | | |
|[Female]| 9 | 38.0 |46.5-49.1|51.3-58.3| 7-11
| | | | (47.7) | (54.9) | (8.7)
| | | | | |
_P. schmidtorum | [Male] | 40 | 30.5 |46.0-51.9|48.2-65.6| 4-6
chamulae_ | | | | (48.2) | (54.9) | (4.7)
| | | | | |
|[Female]| 4 | 31.8 |48.1-52.4|51.4-61.7| 4-9
| | | | (50.5) | (55.7) | (6.2)
| | | | | |
_P. ignicolor_ | [Male] | 13 | 30.5 |45.9-52.2|37.1-47.1| 3-9
| | | | (49.6) | (43.2) | (6.1)
------------------+--------+------+-------+---------+---------+-------

Many workers have used the presence of a bifid subarticular tubercle beneath the fourth finger as a diagnostic character of certain species of hylids. Examination of the subarticular tubercles in _Ptychohyla_ reveals considerable intraspecific variation. Bifid tubercles beneath the fourth finger are found in all species except _P. ignicolor_, which is known from only two specimens. In _P. euthysanota euthysanota_ nearly 60 per cent and in _P. schmidtorum schmidtorum_ about 90 per cent of the specimens have a bifid tubercle beneath the fourth finger on one or both hands. All specimens of _P. leonhardschultzei_ have either a bifid or double tubercle beneath the fourth finger, and some have a bifid distal tubercle beneath the third finger.

FEET.--Members of the _Ptychohyla euthysanota_ group have a weak tarsal fold, whereas in the species comprising the _Ptychohyla schmidtorum_ group the tarsal fold is absent. Webbing on the foot extends to the discs of the third and fifth toes and to the base of the penultimate phalanx of the fourth toe, except in _P. ignicolor_, which has less webbing.

VENTROLATERAL GLANDS.--Breeding males develop thickened, pigmented glandular areas on the sides of the body. In living specimens of _P. schmidtorum_ and _P. ignicolor_ the glands are not readily visible, but in preservative they show as distinctive orange-colored areas. These glands are most distinct in _P. euthysanota_; in many specimens of this species the glands are elevated above the surrounding skin. The extent of the glands is variable (Fig. 2); probably this variability is due to different degrees of development in individual frogs rather than to interspecific differences. All _Ptychohyla ignicolor_ and some _P. schmidtorum chamulae_ have a small, round glandular area on the chin; to my knowledge this does not occur in the other species. Superficial examination of microscopic preparations of the glands reveals no histological differences between species. The glands occupy most of the thickened area and have narrow ducts leading to the exterior. Detailed studies of the histology will be reported elsewhere. Since the glands are developed only in breeding males, it is surmised that the glands are associated with some phase of the breeding activity.

TONGUE.--The shape of the tongue varies intraspecifically. Usually the tongue is ovoid; in some specimens it is barely notched posteriorly, whereas in others it is deeply notched, making the tongue cordiform. Deeply notched cordiform tongues are found in _P. leonhardschultzei_ and _P. schmidtorum_; with the exception of these two species, some individuals of all species have emarginate tongues. Some individuals of all species have tongues that are shallowly notched posteriorly.

Color and Pattern

The dorsum in living frogs of the genus _Ptychohyla_ is primarily yellowish or reddish brown, except in _P. schmidtorum chamulae_ and _P. ignicolor_ in which it is green. Usually there are some darker blotches or reticulations on the dorsum. The venter usually is white; in _P. ignicolor_ it is yellow. The venter is spotted in all members of the _Ptychohyla euthysanota_ group; the species, arranged from least to most spotting ventrally, are: _P. euthysanota euthysanota_, _P. euthysanota macrotympanum_, _P. leonhardschultzei_, and _P. spinipollex_. The last two species also have bold dark spots on the flanks. _Ptychohyla schmidtorum_ lacks spots on the venter, whereas _P. ignicolor_ has small dark flecks ventrally.

_Ptychohyla euthysanota_ and _P. schmidtorum_ have white stripes on the upper lips and on the flanks. All species have some form of a pale stripe above the anus and usually rather distinct white or pale stripes along the ventrolateral edges of the tarsi and forearms. There are no bright or boldly marked flash-colors (colors that are revealed only when the hind limbs are extended), except in _P. ignicolor_, which has bright red flash-colors in the groin and on the thighs. In life the iris varies from several different shades of bronze color to deep red in _P. schmidtorum schmidtorum_.

The degree of metachrosis is moderate. Usually any change of color in life consists only of change in the intensity of color. At times when the over-all coloration is darkened some markings are obscured.

Osteology

The following description of the skull, hyoid, sternum, and prepollex is based on a male specimen of _P. spinipollex_ (KU 68632) that has been cleared and stained. The broad, flat skull (Fig. 3) has a large frontoparietal fontanelle. The ethmoid is large and has a flange laterally. The nasals are of moderate size and in broad contact with the ethmoid, but are separated from one another medially. The anterior half of the maxillary bears a thin, high flange. The anterior process of the squamosal is short and widely separated from the maxillary. The quadratojugal is a small spine-shaped element projecting anteriorly from the ventral base of the quadrate; the quadratojugal does not articulate with the maxillary.

The posteromedian part of the hyoid plate is calcified; from this plate the long bony, posterior cornua (thyrohyales) extend posterolaterally.

The omosternum is calcified, widest anteriorly, and has a convex anterior edge. The calcified xiphisternum is roughly bell-shaped having short lateral processes anteriorly and a deep notch posteriorly.

The swollen thumb is supported by a dorsoventrally flattened spine that does not extrude through the skin.

VARIATION.--In general, the skull varies little. Usually the quadratojugal is present only as a short element attached to the quadrate, but in one specimen of _P. spinipollex_ the quadratojugal articulates with the maxillary and forms a complete quadratojugal-maxillary arch on each side of the skull. One specimen of _P. leonhardschultzei_ has a complete arch on one side and an incomplete arch on the other.

Only _P. spinipollex_ has lateral processes anteriorly on the xiphisternum; in the other species the xiphisternum is deeply bell-shaped.

_Ptychohyla schmidtorum_ and _P. ignicolor_ have slightly longer premaxillaries than the other species. The longer premaxillary is reflected in the larger number of teeth on the bone--9 to 11 (average 10) in four specimens of _P. schmidtorum_ and 10 teeth in one _P. ignicolor_, as compared with 6 to 10 (average 7.9) in seven specimens of the other species. The number of maxillary teeth in the various species are: _P. euthysanota euthysanota_, 43; _P. euthysanota macrotympanum_, 38; _P. leonhardschultzei_, 38 and 40; _P. spinipollex_, 34 and 40; _P. schmidtorum schmidtorum_, 37 and 43; _P. schmidtorum chamulae_, 40 and 41; _P. ignicolor_, 43. The teeth on the premaxillary and anterior part of the maxillary are long, pointed, and terminally curved backwards. Posteriorly on the maxillary the teeth become progressively shorter and blunter.

Variation in number of vomerine teeth is shown in Table 1.

Tadpoles

Tadpoles of the genus _Ptychohyla_ are adapted to live in mountain streams. The bodies are streamlined, and the tails are long and have low fins (Figs. 4 and 5). The mouths are large and directed ventrally. Tadpoles of the two groups of species have strikingly different mouthparts.

Lips of tadpoles of the _Ptychohyla euthysanota_ group (Fig. 6 A-D) are folded laterally; there are 4/6 or sometimes 4/7 tooth-rows. A lateral "wing" projects on either side of the upper beak. The beaks have blunt, peglike serrations. Lips of tadpoles of the _Ptychohyla schmidtorum_ group (Fig. 6 E-G) are greatly expanded and form a funnel-shaped disc; there are 3/3 short tooth-rows. There is no lateral projection or "wing" on either side of the upper beak. The beaks have long, pointed serrations.

Variation in certain structural details and in coloration is discussed for each species and subspecies in the systematic accounts that follow. Sizes, proportions, and numbers of tooth-rows are tabulated in Table 2.

TABLE 2.--COMPARISON OF CERTAIN LARVAL CHARACTERS IN THE SPECIES OF PTYCHOHYLA. (MEANS ARE IN PARENTHESES BELOW THE RANGES.)

==============================+=========+=======+============+==========
| Number |Maximum| Head length|
Species | of | total |------------|Tooth-rows
|specimens| length|Total length|
------------------------------+---------+-------+------------+----------
_P. euthysanota euthysanota_ | 23 | 40.8 | 30.9-37.3 | 4/6
| | | (33.5) |
_P. euthysanota macrotympanum_| 13 | 43.3 | 30.6-33.4 | 4/6
| | | (32.7) |
_P. leonhardschultzei_ | 7 | 47.5 | 29.2-32.7 | 4/6
| | | (31.1) |
_P. spinipollex_ | 32 | 45.0 | 30.2-35.9 | 4/7
| | | (33.0) |
_P. schmidtorum schmidtorum_ | 14 | 42.5 | 28.9-31.2 | 3/3
| | | (29.9) |
_P. schmidtorum chamulae_ | 4 | 45.0 | 26.9-29.3 | 3/3
| | | (27.8) |
_P. ignicolor_ | 2 | 39.6 | 29.6-29.8 | 3/3
| | | (29.7) |
------------------------------+---------+-------+------------+----------

Evidence on the pattern of development of tooth-rows indicates that the inner rows develop first. A small tadpole of _P. euthysanota euthysanota_ has six lower rows and three fully developed upper rows and only the beginning of the first (outer) upper row. A small tadpole of _P. euthysanota macrotympanum_ has four upper rows and five lower rows. In a small tadpole of _P. leonhardschultzei_ the three upper and four lower tooth-rows are well developed; the first upper and fifth lower rows are beginning to develop, and the sixth lower row is absent. In small tadpoles of _P. spinipollex_, the sixth lower row is poorly developed, and the seventh row is absent; large individuals normally have seven lower rows. A small tadpole of _P. schmidtorum chamulae_ has 3/2 tooth-rows.

Breeding Call

Breeding calls of all species and subspecies of _Ptychohyla_ were recorded in the field. Obtaining series of calls of _Ptychohyla_ is difficult because these frogs call mostly from vegetation along roaring mountain streams and only by locating a calling frog some distance from the water or along a quiet stretch of the stream can good recordings be obtained. For example, four individuals of _P. spinipollex_ were recorded, but only one recording was sufficiently free of background noise to be analyzed.

Analysis of breeding calls supports the division of the genus _Ptychohyla_ into two groups of species. The call of each member of the _Ptychohyla euthysanota_ group consists of a single long note, whereas the call of species in the _Ptychohyla schmidtorum_ group consists of a series of short notes. Since no differences were found between the calls of subspecies of any given species, the following discussion of breeding calls pertains to species. These calls are described briefly below and at greater length in the systematic accounts farther on. Audiospectrographs of the breeding calls are shown in Plate 11, and comparisons of the characteristics of the calls are given in Table 3.

Audiospectrographs of the breeding calls of the
five species of _Ptychohyla_:

(A) _P. spinipollex_ (KU Tape No. 41),
(B) _P. euthysanota macrotympanum_ (KU Tape No. 48),
(C) _P. leonhardschultzei_ (UMMZ Tape No. 525),
(D) _P. schmidtorum chamulae_ (KU Tape No. 52),
(E) _P. ignicolor_ (UMMZ Tape No. 526).]

TABLE 3.--COMPARISON OF THE BREEDING CALLS OF PTYCHOHYLA

--------------------------------------------------------------------------
----------------+----+--------+-----------+---------+---------+-----------
| | Notes | Duration | Pulses |Frequency| Dominant
Species |Num-|per call| of note | per | range | frequency
| ber| group | (seconds) | second | (cps) | (cps)
----------------+----+--------+-----------+---------+---------+-----------
_P. spinipollex_| 1 | 1 | .46 | 147 |3000-5100| 4300
| | | | | |
_P. euthysanota_| 7 | 1 | .62 | 95.3 |1800-4200| 3070
| | | (.60-.65) | (91-102)| |(3000-3200)
| | | | | |
_P. leonhard- | 2 | 1 | .79 | 77 |1500-3500| 2750
schultzei_| | | (.62-.95) | (76-78) | |(2700-2800)
| | | | | |
_P. schmidtorum_| 6 | 8.5[A] | .064 | 110 |1400-5800| 3400
| | (8-9) |(.054-.070)| (96-121)| |(3350-3450)
| | | | | |
_P. ignicolor_ | 2 | 12[A] | .079 | 126 |1000-5000| 3150
| |(11-13) |(.078-.080)|(123-129)| |(3100-3200)
----------------+----+--------+-----------+---------+---------+-----------

[Footnote A: Only an analysis of the long series of calls is given
here; see text for explanation.]

_P. spinipollex_ (Pl. 11A).--One long note is repeated at intervals of 45 seconds to four minutes and has an average dominant frequency of 4300 cycles per second.

_P. euthysanota_ (Pl. 11B).--One long note is repeated six to nine times at intervals of 2.7 to 3.4 seconds and has an average dominant frequency of 3070 cycles per second.

_P. leonhardschultzei_ (Pl. 11C).--One long note is repeated once after 10 to 13 seconds and has an average dominant frequency of 2750 cycles per second.

_P. schmidtorum_ (Pl. 11D).--The complete call consists of one short series of notes alternating with two long series. Numbers of notes per series in one individual having a typical call were 5-8-8-3-9-9. The average dominant frequency of notes in the short and long series alike is 3400 cycles per second.

_P. ignicolor_ (Pl. 11E).--The complete call consists of a short series of notes alternating with a long series. In one complete recording the numbers of notes in these series were 4-13-3-11. The notes in the short series have an average dominant frequency of 2100 cycles per second, whereas the notes in the long series have an average dominant frequency of 3150 cycles per second. The four series of notes were given in one minute and 15 seconds.

SYSTEMATIC ACCOUNTS

The museum catalogue numbers of the specimens examined, together with the localities from which they came, are listed at the end of the account of each subspecies or monotypic species. The localities that are represented by symbols on the distribution map (Fig. 7) are in roman type; those that are not represented on the map, because overlapping of symbols would have occurred, are in italic type.

=Ptychohyla= Taylor, 1944

_Ptychohyla_ Taylor, Univ. Kansas Sci. Bull., 30:41, May 15, 1944.
Type, _Ptychohyla adipoventris_ Taylor, 1944 [= _Hyla
leonhardschultzei_ (Ahl), 1934].

_Diagnosis._--Small hylids having stream-adapted tadpoles and differing from other hylid genera in having large ventrolateral glands in breeding males.

_Composition._--Five species, two of which are made up of two subspecies, arranged in two groups of species on the basis of morphological characters of adults and tadpoles and on the basis of breeding calls.

_Distribution._--Moderate elevations from southern Guerrero and northern Oaxaca, Mexico, to northern El Salvador and central Honduras.

KEY TO ADULTS

1. A weak tarsal fold; outer fingers one-third webbed; males
having spiny nuptial tuberosities; color in life tan or brown
with blotches or reticulations, never green; iris bronze color
_P. euthysanota_ group--2

No tarsal fold; outer fingers having only vestige of web;
males lacking nuptial tuberosities; color in life green or
brown; iris red or golden color _P. schmidtorum_ group--5

2. Chest, throat, and flanks usually having brown or black spots;
no distinct white stripe on upper lip or on flanks; a faint
white line usually present above anal opening; a rostral keel 3

Chest, throat, and flanks usually unspotted; distinct white
line on upper lip and on flank present or not; white line
above anal opening faint or well defined; no rostral keel 4

3. Interorbital region much wider than eyelid; spots on throat
and chest black; spots only occasionally present on belly;
flanks marbled with black and white; nuptial spines small, as
many as 80 on one thumb _P. leonhardschultzei_

Interorbital region about as wide as eyelid; spots on chest
and throat brown or black; spots usually present on belly;
flanks having round brown or black spots; nuptial spines
moderate in size, conical, seldom more than 60 on one thumb
_P. spinipollex_

4. A distinct, broad, white lateral stripe usually present;
usually a distinct white line above anal opening; a distinct
white stripe on upper lip _P. euthysanota euthysanota_

No white lateral stripe; a faint white stripe above anal
opening; no distinct white stripe on upper lip
_P. euthysanota macrotympanum_

5. A distinct, broad, lateral stripe; a white stripe on upper
lip expanded to form a large spot below eye; hidden surfaces
of thighs and webs of feet not red in life; internarial region
slightly depressed; diameter of tympanum greater than one-half
diameter of eye 6

No lateral white stripe; no stripe on upper lip; in life
dorsum green, hidden surfaces of thighs and webs of feet
orange tan to bright red, and eye golden color; internarial
region flat; diameter of tympanum less than one-half diameter
of eye _P. ignicolor_

6. Webs of feet and posterior surfaces of thighs pale cream
color; dorsum in life reddish brown; iris bright red
_P. schmidtorum schmidtorum_

Webs of feet and posterior surfaces of thighs pale brown;
dorsum in life green; iris reddish bronze color
_P. schmidtorum chamulae_

KEY TO TADPOLES

1. Lips greatly expanded forming a funnel-shaped mouth;
tooth-rows 3/3 _P. schmidtorum_ group--2

Lips folded laterally, not forming a funnel-shaped mouth;
tooth-rows 4/6 or more _P. euthysanota_ group--4

2. Belly and mouth mottled; tail cream color heavily blotched
with brown 3

Belly dark gray; tail cream color with dense brown flecking,
giving brown appearance _P. schmidtorum chamulae_

3. Belly cream color with brown mottling; no large tubercle at
each end of first lower tooth-row _P. schmidtorum schmidtorum_

Belly grayish green with brown mottling; a large tubercle at
each end of first lower tooth-row _P. ignicolor_

4. Tooth-rows 4/6; cream-colored crescent-shaped mark on
posterior part of body bordered posteriorly by large brown
mark 5

Tooth-rows usually 4/7 (sometimes 4/6); cream-colored
crescent-shaped mark on posterior part of body usually
indistinct, not bordered posteriorly by large brown mark
_P. spinipollex_

5. Caudal musculature uniformly flecked with brown; lower
tooth-rows 1-4 about equal in length to upper rows
_P. euthysanota euthysanota_

Caudal musculature having brown square blotches dorsally on
anterior one-half of tail; lower tooth-rows 1-4 usually
slightly shorter than upper rows 6

6. Dorsal caudal blotches well defined and extending onto sides
of tail; moderately large brown flecks on caudal fin; eye in
life pale reddish brown _P. leonhardschultzei_

Dorsal caudal blotches faint, not extending onto sides of
tail; small brown flecks on caudal fin; eye in life silvery
bronze _P. euthysanota macrotympanum_

The _Ptychohyla euthysanota_ Group

Three species in group; adults having moderate amount of webbing between fingers, and tarsal fold; breeding males having spinous, horny, nuptial tuberosities on pollex; mouths of tadpoles having lateral folds in lips and 4/6 or 4/7 tooth-rows; breeding call consisting of one long note.

=Ptychohyla euthysanota=

_Diagnosis._--Rostral keel absent; nuptial spines in males small; interorbital region much wider than eyelid.

=Ptychohyla euthysanota euthysanota= (Kellogg)

_Hyla euthysanota_ Kellogg, Proc. Biol. Soc. Washington,
41:123-124, June 29, 1928 [Holotype.--USNM 73296 from Los
Esemiles, Depto. Chalatenango, El Salvador; Ruben A. Stirton
collector]. Mertens, Senckenbergiana, 33:169-171, June 15,
1952; Abhand. Senckenbergische Naturf. Gesell., 487:29,
December 1, 1952. Stuart, Proc. Biol. Soc. Washington, 67:169,
August 5, 1954.

_Hyla rozellae_ Taylor, Univ. Kansas Sci. Bull., 28:78-80, pl. 9,
fig. 1, May 15, 1942 [Holotype.--USNM 115039 from Salto de
Agua, Chiapas, Mexico; Hobart M. and Rozella Smith
collectors]. Taylor and Smith, Proc. U. S. Natl. Mus., 95:587,
June 30, 1945. Smith and Taylor, Bull. U. S. Natl. Mus.,
194:86, June 17, 1948. Stuart, Proc. Biol. Soc. Washington,
67:169, August 5, 1954.

_Ptychohyla bogerti_ Taylor, Amer. Mus. Novitates, 1437:13-16,
fig. 5, December 7, 1949 [Holotype.--AMNH 51847 from Rio
Grande, Oaxaca, Mexico; Thomas MacDougall collector]. Stuart,
Proc. Biol. Soc. Washington, 67:169, August 5, 1954.

_Ptychohyla euthysanota_, Duellman, Univ. Kansas Publ. Mus. Nat.
Hist., 13:351, April 27, 1961.

_Diagnosis._--Dorsum tan to reddish brown; venter white; rarely flecked with brown or black; a white stripe on upper lip, on flank, and usually above anus.

_Description._--The following description is based on KU 58008 from Finca La Paz, Depto. San Marcos, Guatemala (Pl. 12). Adult male having a snout-vent length of 35.0 mm.; tibia length, 16.5 mm.; tibia length/snout-vent length, 47.1 per cent; foot length, 14.2 mm.; head length, 11.0 mm.; head length/snout-vent length, 31.4 per cent; head width, 10.7 mm.; head width/snout-vent length, 30.6 per cent; diameter of eye, 3.3 mm.; diameter of tympanum, 1.8 mm.; tympanum/eye, 54.5 per cent. Snout in lateral profile nearly square, slightly rounded above, and in dorsal profile bluntly rounded; canthus pronounced; loreal region moderately concave; lips thick, rounded, and slightly flaring; nostrils protuberant; internarial distance, 3.0 mm.; top of head flat; interorbital distance, 4.1 mm., and approximately a third broader than width of eyelid, 2.9 mm. Moderately heavy dermal fold from posterior corner of eye above tympanum to point above insertion of forelimb, covering upper edge of tympanum; tympanum round, its diameter slightly more than its distance from eye. Forearm moderately robust, having distinct dermal fold on wrist; dermal fold, but no row of tubercles along ventrolateral surface of forearm; pollex only slightly enlarged, bearing triangular shaped patch of small horn-covered spines (128 on right, 134 on left); second and fourth fingers equal in length; subarticular tubercles round, distal one on fourth finger bifid; discs moderate in size, that of third finger equal to diameter of tympanum; no web between first and second fingers; other fingers one-third webbed. Heels broadly overlap when hind limbs adpressed; tibiotarsal articulation reaches to middle of eye; low rounded tarsal fold; inner metatarsal tubercle large, elliptical, and flat; outer metatarsal tubercle small and round; low dermal fold from heel to disc of fifth toe; subarticular tubercles round; length of digits from shortest to longest 1-2-5-3-4; third and fifth toes webbed to base of disc; fourth toe webbed to proximal end of penultimate phalanx; thin dermal fold from inner metatarsal tubercle to disc of first toe; disc smaller than on fingers. Anal opening at the level of the upper edge of thighs; anal flap short; anal opening bordered above by thin transverse dermal fold and laterally by heavy dermal fold. Skin of dorsum and ventral surfaces of forelimbs and shanks smooth; that of throat, belly, and ventral surfaces of thighs granular. Ventrolateral glands moderately developed, not reaching axilla or groin and broadly separated midventrally. Tongue ovoid, emarginate, and only slightly free posteriorly; vomerine teeth 2-2, situated on small triangular elevations between ovoid inner nares; openings to vocal sac large, one situated along inner posterior edge of each mandibular ramus.

Dorsal ground-color of head, body, and limbs dull reddish brown with irregular dark brown reticulations on head and body and dark brown transverse bands on limbs; dorsal surfaces of first and second fingers and webbing on hand cream color; dorsal surfaces of third and fourth fingers dull brown; anterior surfaces of thighs dull creamy yellow; posterior surfaces of thighs dull brown; tarsi and toes tan with brown flecks; webbing of feet brown; faint creamy white stripe along lateral edges of tarsi and forearms; thin white line along edge of upper lip; distinct white stripe above and beside anal opening; axilla white; throat, chest, belly, and ventral surfaces of forelimbs creamy white; flanks white, separated from pale venter by a row of partly connected dark brown spots; ventral surfaces of thighs dull creamy yellow; feet grayish brown; ventrolateral glands pale grayish brown; small brown flecks on periphery of chin.

In life the dorsal ground-color was pale reddish brown (Orange-Cinnamon); dorsal reticulations dark brown (Chocolate); dorsal surfaces of first and second fingers and webbing on hands creamy tan (Light Pinkish Cinnamon); posterior surfaces of thighs reddish brown (Vinaceous-Tawny); webbing of feet gray (Deep Mouse Gray); throat and belly grayish white (Pale Gull Gray); ventral surfaces of hind limbs creamy white (Marguerite Yellow); spots on flanks dark brown (Warm Sepia); iris reddish bronze (Apricot Orange).

_Variation._--No geographic variation in structural characters is discernible; variation in size and proportions is given in Table 1. Of 32 adults examined, seven have the tongue shallowly notched posteriorly; in the others the tongue is emarginate. Twenty specimens have a bifid subarticular tubercle beneath the fourth finger; in the others there are no bifid tubercles.

The coloration described above is typical of the 16 specimens available from Finca La Paz. The living coloration at night, when the frogs were collected, was somewhat darker than the living colors described above, which were recorded for the frogs the morning after collection, at which time one individual had a pale reddish brown dorsum (Orange-Cinnamon) with dull olive green (Deep Grape Green) reticulations on the back and transverse bands on the limbs; the dorsal surfaces of the first and second fingers and the discs on the third and fourth fingers were orange (Mikado Orange).

More than half of the specimens from Finca La Paz agree in all essential characters with the description given above. The distinctness of the white stripe on the upper lip is variable; in two individuals the stripe is barely discernible. Likewise, in some individuals the white stripe on the flanks is not distinct, either because there are few or no brown spots separating the stripe from the pale venter, or because the ventrolateral gland has diffused the pale color on the flanks. There is some noticeable variation in dorsal coloration, either through a greater or lesser development of dark pigment. One specimen (KU 58007) is grayish tan above with dark brown markings; the posterior surfaces of the thighs are dull grayish yellow; the first and second fingers and the webbing on the hands are pale yellowish gray; the belly and throat are dusty white; the flecks on the throat are gray; the ventral surfaces of the feet are grayish brown. Dark individuals, such as KU 58009 have a uniform dark brownish black dorsum; the belly is cream; the first and second fingers and the webbing on the hands are dull creamy tan; the dorsal and ventral surfaces of the feet are dark brown. In KU 58013 there is a heavy suffusion of brown on the throat and flanks. Two specimens have scattered white flecks on the dorsum.

The reddish brown dorsal ground-color with dark brown reticulations on the head and body and dark brown transverse bands on the limbs seems to be rather constant throughout the range of the subspecies. Likewise, the presence of the white stripe on the upper lip and the white stripe around the anal opening are present on most specimens. In breeding males having well-developed ventrolateral glands the lateral white stripe often is obliterated.

_Description of Tadpole._--The following description is based on KU 60042 from Finca La Paz, Depto. San Marcos, Guatemala (Figs. 4A and 6A). No limb buds; total length, 35.8 mm.; body length, 11.2 mm.; body length/total length, 31.3 per cent. Body moderately depressed, slightly wider than deep, ovoid in dorsal profile; mouth directed ventrally; eyes small, directed dorsolaterally; nostrils slightly protuberant and directed anteriorly, closer to eye than snout; spiracle sinistral and posteroventrad to eye; anal tube dextral. Caudal fin low, rounded posteriorly; depth of caudal musculature about one-half greatest depth of caudal fin; musculature extends nearly to tip of tail.

Mouth large; lips having deep lateral folds; two complete rows of papillae on lips; five to six rows of papillae laterally. Beaks moderately developed, bearing peglike serrations; slender lateral projections on upper beak; tooth-rows 4/6; upper rows subequal in length, second longest; fourth row interrupted medially; lower rows complete; lower rows 1-4 equal in length to upper rows; fifth lower row somewhat shorter; sixth lower row short.

Body brown above; tip of snout cream color; grayish cream color below; caudal musculature creamy tan; caudal fin transparent; cream-colored crescent-shaped mark on posterior edge of body and anterior part of caudal musculature, bordered posteriorly by dark brown blotch; scattered brown flecks on caudal musculature and posterior part of caudal fin. Eye bronze color in life.

_Variation._--The variation in size and proportions is given in Table 2. In some specimens the first upper tooth-row is irregular, sometimes broken, and often shorter than other upper tooth-rows. Usually the fourth upper and first lower, and sometimes the sixth lower, tooth-rows are interrupted medially. One specimen has a short, irregular, seventh lower tooth-row; all others have six.

The cream-colored crescent-shaped mark usually is distinct. The brown blotch posterior to this mark is variously shaped ranging from a narrow vertical bar to a triangular blotch. Brown flecks seldom are present on the anterior part of the ventral caudal fin.

_Comparisons._--Aside from the characters given in the diagnosis, _P. euthysanota euthysanota_ can be distinguished from both _P. spinipollex_ and _P. leonhardschultzei_ by the absence of bold black and white marbling on the flanks; furthermore, from the former it can be distinguished by having more and smaller horny nuptial spines and from the latter by having the snout, in lateral profile, rounded above and not acutely angulate. _Ptychohyla euthysanota euthysanota_ differs from _P. euthysanota macrotympanum_ by normally having a darker dorsal color, broader stripe on upper lip, and a distinct lateral stripe.

Occurring sympatrically with _Ptychohyla euthysanota euthysanota_ are several species of _Plectrohyla_, all of which differ in having a bony prepollex, rather rugose skin on the dorsum, and more squat bodies. Other sympatric species are _Ptychohyla schmidtorum schmidtorum_, which lacks a tarsal fold and nuptial spines and has a red eye in life, _Hyla salvadorensis_, which has a green dorsum and lacks spinous nuptial tuberosities, and _Hyla sumichrasti_, a small yellow frog usually lacking vomerine teeth.

_Life History._--This subspecies breeds in clear, swift mountain streams. Males call from stems and leaves of plants at the edge of, or overhanging, the streams. The breeding call consists of a soft "wraack," repeated at intervals of three to four seconds. Each note has a duration of 0.60 to 0.65 seconds and has 91 to 102 pulses per second; the dominant frequency falls between 3000 and 3200 cycles per second.

Tadpoles in various stages of development were found at Finca La Paz, Guatemala, in late July. This indicates that there is either extreme differential growth, or, more probably, an extended breeding season. A tadpole having a body length of 6.8 mm. and a total length of 19.1 mm. has a short median first upper tooth-row; lower tooth-rows 3-6 are only two-thirds as long as lower rows 1 and 2. Two recently metamorphosed young have snout-vent lengths of 14.2 and 14.8 mm.; they are colored like the adults.

_Remarks._--The type specimen of _Hyla euthysanota_ Kellogg (1928:123) is a female; therefore, when Taylor (1944) proposed the name _Ptychohyla_ for hylids having ventrolateral glands in breeding males, he was unaware that _Hyla euthysanota_ was a member of this group. In his description of _Hyla rozellae_, Taylor (1942) did not compare his specimens with _Hyla euthysanota_, but instead placed _H. rozellae_ with _H. loquax_ and _H. rickardsi_. The type series of _H. rozellae_ consists of one large adult female and several metamorphosing young. Taylor (1949:16) based the description of _Ptychohyla bogerti_ on two males and compared these specimens with _P. adipoventris_ Taylor [= _P. leonhardschultzei_ (Ahl)]. Thus, in a period of 22 years the females of this species were given two names and the male another. Stuart (1954:169) suggested that _Hyla euthysanota_ and _Hyla rozellae_ were _Ptychohyla_. Now that sufficient specimens are available from throughout the range it is possible to determine that the various named populations are conspecific.

_Distribution._--This subspecies inhabits cloud forests at elevations of 660 to 2200 meters on the Pacific slopes of the Sierra Madre from extreme eastern Oaxaca and western Chiapas, Mexico, through Guatemala to northern El Salvador; probably it occurs also in southwestern Honduras. Aside from the specimens listed below, three in the Frankfurt Museum from Depto. Santa Ana, El Salvador (44571, Hacienda San Jose; 43040, Hacienda Los Planes; 65119, Miramundo) are listed by Mertens (1952:29).

_Specimens examined._--MEXICO: _Chiapas: Cascarada, 30 km. W of Ciltapec_, UMMZ 87851-2; Cerro Ovando, UMMZ 87853-4; Chicomuselo, UMMZ 94439-40; Finca Juarez, 28 km. N of Escuintla, USNM 115052-5; _Las Nubes, Cerro Ovando_, USNM 115030-8; Salto de Agua, USNM 115039-51. _Oaxaca_: Cerro Pecho Blanco, UIMNH 40963; between La Gloria and Cerro Azul, UIMNH 40976-7; Rio Grande, AMNH 51847-8; Santo Tomas Tecpan, UIMNH 41071.

GUATEMALA: _San Marcos_: Finca La Paz, 2 km. W of La Reforma, KU 58001-14, 59937 (skeleton), 60042-3 (tadpoles), 60044 (4 young), MCZ 34997, UMMZ 107739, 123151-7 (tadpoles); Finca Pirineos, Rio Samala, CNHM 35066. _Santa Rosa_: Finca La Gloria, UMMZ 123148 (tadpoles), 123150 (tadpoles). _Solola_: Finca Santo Tomas, UMMZ 123149 (tadpoles); Olas de Moca, near Moca, CNHM 20208.

EL SALVADOR: _Chalatenango_: Los Esemiles, USNM 73296. _Santa Ana_: Miramundo, CNHM 65120.

=Ptychohyla euthysanota macrotympanum= (Tanner)

_Hyla macrotympanum_ Tanner, Great Basin Nat., 17:52-53, July 31,
1957 [Holotype.--AMNH 62141 (formerly BYU 13752) from 10 miles
east of Chiapa de Corzo, Chiapas, Mexico; Robert Bohlman
collector].

_Ptychohyla macrotympanum_, Duellman, Univ. Kansas Publ. Mus. Nat.
Hist., 13:351, April 27, 1961.

_Diagnosis._--Dorsum usually pale tan; venter white with scattered brown or black flecks; a thin white stripe on upper lip and another above anal opening; no distinct white stripe on flanks.

_Description._--The following description is based on KU 58049 from Linda Vista, Chiapas, Mexico (Pl. 13). Adult male having a snout-vent length of 38.0 mm.; tibia length, 19.5 mm.; tibia length/snout-vent length, 51.3 per cent; foot length, 15.7 mm.; head length, 11.8 mm.; head length/snout-vent length, 31.1 per cent; head width, 11.7 mm.; head width/snout-vent length, 30.8 per cent; diameter of eye, 3.8 mm.; diameter of tympanum, 2.1 mm.; tympanum/eye, 55.2 per cent. Snout in lateral profile nearly square, slightly rounded above, and in dorsal profile bluntly rounded; canthus pronounced; loreal region concave; lips thick, rounded, and slightly flaring; nostrils protuberant; internarial distance, 3.1 mm.; top of head flat; interorbital distance, 3.8 mm., and approximately a fourth broader than width of eyelid, 3.1 mm. A moderately heavy dermal fold from posterior corner of eye above tympanum to point above insertion of forelimb, covering upper edge of tympanum; tympanum round, its diameter equal to its distance from eye. Forearm moderately robust, having a distinct dermal fold on wrist; dermal fold, but no row of tubercles along ventrolateral surface of forearm; pollex only slightly enlarged, bearing triangular patch of small horn covered spines (94 on right, 100 on left); fourth finger slightly longer than second; subarticular tubercles round, none bifid; discs moderate in size, that of third finger equal to diameter of tympanum; vestige of web between first and second fingers; other fingers one-third webbed. Heels broadly overlap when hind limbs adpressed; tibiotarsal articulation reaches to middle of eye; weak tarsal fold on distal two-thirds of tarsus; inner metatarsal tubercle large, elliptical, and flat; outer metatarsal tubercle small and round; no dermal fold from heel to disc of fifth toe; subarticular tubercles round; length of digits from shortest to longest 1-2-5-3-4; third toe webbed to base of disc; fifth toe webbed to middle of penultimate phalanx; fourth toe webbed to proximal end of penultimate phalanx; no fold of skin from inner metatarsal tubercle to base of disc on first toe; discs much smaller than on fingers. Anal opening near upper edge of thighs; short anal flap bordered above by thin dermal fold; small tubercles and heavy dermal fold lateral to anal opening. Skin of dorsum and ventral surfaces of fore limbs and shanks smooth; that of throat, belly, and ventral surfaces of thighs granular. Ventrolateral glands weakly developed, not reaching axilla or groin and broadly separated midventrally. Tongue ovoid, shallowly notched posteriorly, and barely free behind; vomerine teeth 2-2, situated on small triangular elevations between ovoid inner nares; openings to vocal sac large, one situated along inner posterior edge of each mandibular ramus.

Dorsal ground-color of head, body, and limbs pale pinkish tan with the greatest part of head and body covered by large gray interconnected blotches; black flecks over most of dorsum; grayish brown transverse bands on shanks; dorsal surfaces of first and second fingers pale grayish yellow; dorsal surfaces of third and fourth fingers and webbing on hand pale grayish tan; anterior surfaces of thighs pale flesh-color; posterior surfaces of thighs pale grayish yellow; dorsal surfaces of tarsi and toes pale grayish tan with black flecks; webbing of feet pale gray; faint creamy white stripes along ventrolateral edges of tarsi and forearms; a very thin white line along edge of upper lip; a narrow grayish white stripe above anal opening; axilla gray; throat, chest, belly, and ventral surfaces of forelimbs pale grayish white; ventral surfaces of hind limbs cream color; flanks gray flecked with brown; ventral surfaces of feet grayish tan; ventrolateral glands pinkish tan; anterior one-half of chin flecked with brown.

In life the dorsum was pale tan (Pinkish Buff); the dark markings on dorsum dull brown (Tawny-Olive); tarsi pale tan (Pale Pinkish Buff); flanks pinkish tan (Pale Cinnamon-Pink); iris coppery bronze (Capucine Orange).

_Variation._--The few specimens from a limited geographic region preclude any analysis of geographic variation. All specimens, except the one described above, have the fifth toe webbed to the base of the disc. Many individuals have a bifid subarticular tubercle beneath the fourth finger. The shape of the posterior edge of the tongue varies from nearly straight and shallowly notched to bluntly rounded and emarginate. Two females (KU 58050-1) have more pointed snouts in dorsal profile than do males.

Some specimens, such as KU 58048, are notably darker than the specimen described above; in dark specimens the dorsum is brown with dark brown markings; all fingers and the webbing on the hand are brown. The tarsi and feet are like those in the specimen described above, but the posterior surfaces of the thighs are yellowish tan heavily suffused with brown; the venter is cream color. In life KU 58048 had a brown (Verona Brown) dorsum with dark brown (Chocolate) markings. KU 58047 is slightly darker than KU 58048 and has scattered small white flecks on the dorsum. All specimens have the thin white line on the upper lip, but in some individuals it is indistinct. The grayish white line above the anus is present in all specimens.

_Description of Tadpole._--The following description is based on KU 60049 from Rio Hondo, 9.5 kilometers south of Pueblo Nuevo Solistahuacan, Chiapas, Mexico (Figs. 4B and 6B). No limb buds; total length, 36.2 mm.; body length, 11.1 mm.; body length/total length, 30.6 per cent. Body moderately depressed, slightly wider than deep, ovoid in dorsal profile; mouth directed ventrally; eyes small, directed dorsolaterally; nostrils slightly protuberant and directed anteriorly, somewhat closer to eye than snout; spiracle sinistral and posteroventrad to eye; anal tube dextral. Caudal fin low, acutely rounded posteriorly; depth of caudal musculature slightly more than one-half greatest depth of caudal fin; caudal musculature extending nearly to tip of tail.

Mouth large; lips having deep lateral folds; two complete rows of papillae on lips; five or six rows of papillae laterally. Beaks moderately developed, bearing small peglike serrations; moderately wide lateral projections on upper beak; tooth-rows 4/6; upper rows subequal in length; fourth row interrupted medially; length of lower rows 1-4 subequal to upper rows; fifth and sixth lower rows decreasing in length; first lower row interrupted medially.

Body brown above; tip of snout cream color; venter creamy white; caudal musculature creamy tan; caudal fin transparent; cream-colored crescent-shaped mark on posterior edge of body and anterior part of caudal musculature, bordered posterodorsally by dark brown blotch; four dark brown blotches on dorsum of anterior part of caudal musculature; scattered brown flecks on caudal musculature and fin; eye silvery bronze in life.

_Variation._--The variation in size and proportions is given in Table 2. All specimens have 4/6 tooth-rows; in some the first lower row is interrupted medially. Specimens from Jacaltenango and two kilometers west of San Pedro Necta, Depto. Huehuetenango, Guatemala, have weakly developed sixth lower tooth-rows.

The cream-colored crescent-shaped mark is distinct in all specimens; the dorsal blotches on the anterior part of the caudal musculature are narrow and do not extend far onto the sides of the tail. The blotches are most distinct in small tadpoles and sometimes indistinct in large ones.

_Comparisons._--_Ptychohyla euthysanota macrotympanum_ can be distinguished from both _P. spinipollex_ and _P. leonhardschultzei_ by the absence of bold black and white marbling on the flanks, as well as by the characters given in the diagnosis; furthermore, from the former it differs in having more and smaller horny nuptial tuberosities and from the latter by having the snout, in lateral profile, rounded above instead of angulate. _Ptychohyla euthysanota macrotympanum_ differs from _P. e. euthysanota_ by normally having a paler dorsum, narrower stripe on upper lip, and no distinct lateral stripe.

_Ptychohyla euthysanota macrotympanum_ occurs sympatrically with _Plectrohyla guatemalensis_ and _P. matudai matudai_. Each of the last two has a bony prepollex, rather rugose skin on the dorsum, and more squat body. Other sympatric species are _Hyla walkeri_, which has a green dorsum with brown markings and a rather pointed snout, and _Hyla sumichrasti_, a small yellow frog usually lacking vomerine teeth.

_Life History._--This species breeds in clear mountain streams in mixed pine and broad-leafed forest. Males call from trees and bushes along the streams. The breeding call consists of a soft "wraack," repeated three to nine times with intervals of 2.7 to 3.4 seconds between notes. Each note has a duration of 0.60 to 0.65 second, and a rate of 92 to 100 pulses per second; the dominant frequency falls between 3000 and 3200 cycles per second (Pl. 11B). The call is indistinguishable from that of _P. e. euthysanota_.

Tadpoles in various stages of development were found in the Rio Hondo, Chiapas, on June 16, 1960. The smallest tadpole has a total length of 24.1 mm.; in this individual the sixth lower tooth row has barely started to develop. A metamorphosing frog taken at the same time has a snout-vent length of 19.8 mm., a short remnant of the tail, and the mouth and tongue developed, whereas another individual having a snout-vent length of 17.8 mm. and a tail 31.0 mm. in length still has larval teeth. Three completely metamorphosed juveniles collected by L. C. Stuart at Jacaltenango, Guatemala, on June 6 and 7, 1955, have snout-vent lengths of 16.0, 16.0, and 16.1 mm.

_Remarks._--Tanner (1957:52) based the description of _Hyla macrotympanum_ on a single female, which, of course, lacked the characters diagnostic of _Ptychohyla_. On the basis of general external characters Tanner suggested that _Hyla macrotympanum_ was related to _H. miotympanum_, from which it differed in having a larger tympanum and a bifid subarticular tubercle beneath the fourth finger. The collection of additional females, together with males of the species, has shown that _Hyla macrotympanum_ is a _Ptychohyla_.