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.

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_.

Intergradation between _Ptychohyla euthysanota_ and _P. macrotympanum_ has not been demonstrated. Currently their ranges are separated by the dry valleys of the Rio Grijalva and Rio Cuilco. The similarity in structure of the adults and tadpoles and the indistinguishable breeding calls are the basis for considering the two populations subspecies.

_Distribution._--This species occurs in mixed pine and broad-leafed forests at elevations of 700 to 1700 meters on the southern slopes of the Chiapan Highlands and Sierra de Cuchumatanes, in Guatemala. These forests are on the south facing slopes north of the valleys of the Rio Grijalva and Rio Cuilco.

_Specimens examined._--MEXICO: _Chiapas_: 6 km. NE of Chiapa de Corzo, TCWC 16183; 16 km. E of Chiapa de Corzo, AMNH 62141; Linda Vista, 2 km. NW of Pueblo Nuevo Solistahuacan, KU 58049-51, 59939 (skeleton); _Rio Hondo, 9.5 km. S of Pueblo Nuevo Solistahuacan_, KU 58047-8, 60046-7, 60048-9 (tadpoles); San Fernando, MZTG 15, 17; Tonina (ruins), KU 41592.

GUATEMALA: _Huehuetenango_: Jacaltenango, UMMZ 123139 (tadpoles); 0.5 km. E of Jacaltenango, UMMZ 123142-3; 2 km. S of Jacaltenango, UMMZ 123141; 2 km. W of San Pedro Necta, UMMZ 123140 (tadpoles).

=Ptychohyla leonhardschultzei= (Ahl)

_Hyla leonhard-schultzei_ Ahl, Zool. Anz., 106:185-186, fig. 1, April 15, 1934 [Holotype.--ZMB 34353 from Malinaltepec, Guerrero, Mexico; Leonhard Schultze collector]. Smith and Taylor, Bull. U. S. Natl. Mus., 184:87, June 17, 1948.

_Hyla godmani_, Ahl, Zool. Anz., 106:186, April 15, 1934.

_Hyla pinorum_ Taylor, Proc. Biol. Soc. Washington, 50:46-48, pl. 2, fig. 2, April 21, 1937 [Holotype.--UIMNH 25049 from Agua del Obispo, Guerrero, Mexico; Edward H. Taylor collector]. Smith and Taylor, Bull. U. S. Natl. Mus., 194:87, June 17, 1948.

_Ptychohyla adipoventris_ Taylor, Univ. Kansas Sci. Bull., 30:41-45, May 15, 1944 [Holotype.--UIMNH 25047 from Agua del Obispo, Guerrero, Mexico; Edward T. Taylor collector]. Smith and Taylor, Bull. U. S. Natl. Mus., 194:91, June 17, 1948. Taylor, Amer. Mus. Novitates, 1437:16, December 7, 1949. Stuart, Proc. Biol. Soc. Washington, 67:169, August 5, 1954.

_Hyla milleri_ Shannon, Proc. U. S. Natl. Mus., 101:473-477, figs. 92b, 93a-c, May 17, 1951 [Holotype.--USNM 123700 from San Lucas Camotlan, Oaxaca, Mexico; Walter S. Miller collector].

_Ptychohyla leonhard-schultzei_, Duellman, Herpetologica, 16:191-197, figs. 1-3, September 23, 1960; Univ. Kansas Publ. Mus. Nat. Hist., 13:351, April 27, 1961.

_Diagnosis._--Rostral keel present; snout in lateral profile not rounded above; interorbital region much broader than eyelid; distal subarticular tubercle beneath fourth finger bifid or double; no white stripe on edge of upper lip; flanks white with black spots.

_Description._--The following description is based on KU 64117 from Vista Hermosa, Oaxaca, Mexico (Pl. 14). Adult male having a snout-vent length of 35.6 mm.; tibia length, 18.0 mm.; tibia length/snout-vent length, 50.5 per cent; foot length, 14.3 mm.; head length, 10.7 mm.; head length/snout-vent length, 30.1 per cent; head width, 10.6 mm.; head width/snout-vent length, 29.8 per cent; diameter of eye, 3.6 mm.; diameter of tympanum, 1.8 mm.; tympanum/eye, 50.0 per cent. Snout in lateral profile square, not rounded above, and in dorsal profile rounded with pointed tip resulting from vertical rostral keel; canthus pronounced; loreal region barely concave; lips thick, rounded, and barely flaring; nostrils protuberant; internarial distance, 3.2 mm.; top of head flat; interorbital distance, 3.8 mm., and approximately a fifth broader than width of eyelid, 3.2 mm. A moderately heavy dermal fold from posterior corner of eye above tympanum and curving ventrad to anterior edge of insertion of forelimb, covering upper edge of tympanum; tympanum round, its diameter equal to its distance from eye. Forearm moderately robust, having distinct dermal fold on wrist; row of small, low, rounded tubercles along ventrolateral surface of forearm; pollex only slightly enlarged, bearing triangular patch of small horn-covered spines (56 on right, 62 on left); second finger noticeably shorter than fourth; subarticular tubercles round, distal ones on third and fourth toes bifid; discs moderate in size, that of third finger slightly larger than 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; a low rounded tarsal fold on distal half of tarsus; inner metatarsal tubercle elevated, flat, and elliptical; outer metatarsal tubercle at base of fourth toe, round; row of low, sometimes indistinct, tubercles from heel to base of fifth toe; subarticular tubercles round; length of digits from shortest to longest 1-2-3-5-4, third and fifth being about equal in length; third and fifth toes webbed to base of disc; fourth toe webbed to base of penultimate phalanx; discs of toes much smaller than on fingers. Anal opening near dorsal surface of thighs; short anal flap; opening bordered laterally by heavy dermal fold and ventrolaterally by large tubercles. 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, reaching axilla but not to groin and broadly separated midventrally. Tongue cordiform, shallowly notched behind and barely free posteriorly; vomerine teeth 4-3, situated on transverse 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 tan with large interconnected dark brown blotches on head and body and broad dark brown transverse bands on limbs; dorsal surfaces of first and second fingers and of webbing of hands pale brown; dorsal surfaces of third and fourth fingers dark brown; anterior surfaces of thighs flesh-color; posterior surfaces of thighs brown; dorsal surfaces of tarsi and feet dark brown; narrow white stripe along ventrolateral edges of forearms and tarsi; a faint creamy white stripe above anal opening; axilla white; flanks creamy white, boldly spotted with black; throat and chest white; ventral surfaces of tarsi and feet dark brown; other ventral surfaces dusty cream color; large brown spots on chin and anterior part of abdomen.

In life the dorsum was reddish brown (Orange-Cinnamon) with dark brown (Chocolate) blotches; first and second fingers and webbing on hand pale reddish brown (Cinnamon); webbing on feet dark brown (Clove Brown); flanks pale creamy white (Pale Olive Buff) with dark brown (Bone Brown) spots; iris reddish bronze (Apricot Orange).

_Variation._--No noticeable geographic variation is apparent in the few available specimens; variations in proportions are given in Table 1. The distal subarticular tubercle of the fourth finger is either bifid or double in all specimens; that on the third finger usually is bifid, sometimes single. The vertical rostral keel is prominent in all freshly preserved specimens; in some older specimens it is indistinct. The tongue always is notched posteriorly; in some individuals the notch is shallow; in others it is deep.

Some specimens are paler and less boldly marked than the specimen described above. All specimens from Agua del Obispo and some specimens from the northern slopes of the Sierra Madre Oriental in Oaxaca have a pale tan dorsum with brown markings. In most individuals the white color in the axilla extends onto the posterior edge of the upper arm. The creamy white color of the flanks is constant and usually extends slightly dorsad in the inguinal region. The white stripe above, and sometimes continuing down beside, the anal opening varies from a thin indistinct line or row of flecks to a distinct continuous stripe. Two specimens have dark brown spots on the belly; in the others the spots are confined to the flanks and throat.

_Description of tadpole._--The following description is based on KU 68556 from 7.5 kilometers south of Yetla, Oaxaca, Mexico (Figs. 4C and 6C). No limb buds; total length, 37.3 mm.; body length, 12.2 mm.; body length/total length, 32.7 per cent; body slightly depressed, barely wider than deep, ovoid in dorsal profile; mouth directed ventrally; eyes small, directed dorsolaterally; nostrils barely protuberant and directed anterolaterally, about midway between snout and eye; spiracle sinistral and posteroventrad to eye; anal tube dextral. Caudal fin low, bluntly rounded posteriorly; greatest depth of caudal musculature about one-half 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 seven rows of papillae laterally; beaks moderately developed, bearing short 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 equal to upper rows; fifth and sixth lower rows shorter; first lower row interrupted medially.

Body brown above; tip of snout brown; venter creamy gray; caudal musculature creamy tan; caudal fin transparent; cream-colored crescent-shaped mark on posterior edge of body; dark brown flecks on caudal musculature and all except anterior two-thirds of ventral caudal fin; large brown square blotches on dorsum of caudal fin; eye reddish brown in life.

_Variation._--The variation in size and proportions is given in Table 2. With the exception of one specimen having a short, broken, seventh tooth-row, all specimens have 4/6 tooth-rows that are like those described above. In some specimens the brown blotches on the dorsum of the caudal musculature are fused and marked with cream-colored flecks.

_Comparisons._--_Ptychohyla leonhardschultzei_ differs from all other members of the _Ptychohyla euthysanota_ group in having a square snout, and further differs from _P. spinipollex_ in more numerous and smaller nuptial spines and in transverse, instead of posteromedially slanting, vomerine processes between the inner nares. _Ptychohyla leonhardschultzei_ differs from _P. euthysanota_ in having a rostral keel and in having white flanks boldly spotted with black.

All small hylids that are sympatric with _Ptychohyla leonhardschultzei_ are either yellow (_Hyla dendroscarta_ and _H. melanomma_) or green (_Hyla erythromma_, which has a red eye, _Hyla hazelae_, which has a black line on the canthus, and _Ptychohyla ignicolor_, which has red flash colors on the thighs).

_Life History._--This frog has been found along streams in cloud forests and in pine-oak forest. Males call from vegetation along the stream or from rocks in and at the edge of the stream. The call is a single, long, soft "wraack," repeated at intervals of anywhere from several seconds to three or four minutes. Each note has a duration of 0.62 to 0.95 of a second and a rate of 76 to 78 pulses per second; the dominant frequency falls between 2700 and 2800 cycles per second (Pl. 11C).

Tadpoles were found in several streams in northern Oaxaca. A tadpole having a total length of 21.1 mm. has three upper and four lower tooth-rows well developed; the fourth upper and fifth lower rows are weakly present, and the sixth lower row has not started to develop. Two metamorphosed young have snout-vent lengths of 15.2 and 15.5 mm.

_Remarks._--Four specific names have been applied to this species. Ahl (1934:185) based his description of _Hyla leonhardschultzei_ on a small, poorly preserved female. Taylor (1944:41) proposed the generic name _Ptychohyla_ for a species (named therein as _P. adipoventris_) of hylid having ventrolateral glands and horn-covered nuptial spines. Obviously, Taylor was unaware that _Hyla leonhardschultzei_ was the same species. Earlier Taylor (1937:46) described _Hyla pinorum_. The types of all of these species came from the Pacific slopes of the Sierra del Sur in Guerrero. Examination of the types and other available specimens shows that they are representatives of a single species. The type of _Hyla pinorum_ is an immature male having a snout-vent length of 26.7 mm. All of these specimens have the square snout and black and white flanks characteristic of _Ptychohyla leonhard-schultzei_. Although Shannon (1951:473) based his description of _Hyla milleri_ on a male having well-developed ventrolateral glands, he overlooked the presence of these glands in his description and discussion of relationships. The acquisition of more specimens from northern Oaxaca has shown that _Hyla milleri_ is the same as _Ptychohyla leonhardschultzei_.

_Distribution._--This species is known from pine-oak forest and cloud forest on the Pacific slopes of the Sierra Madre del Sur in Guerrero and Oaxaca and from the Atlantic slopes of the Sierra Madre Oriental in northern Oaxaca. Specimens have been collected at elevations between 700 and 1650 meters. Probably the species occurs in humid forests at similar elevations around the eastern end of the Mexican Highlands in Oaxaca.

_Specimens examined._--MEXICO: _Guerrero_: Agua del Obispo, CNHM 123489-90, 126651, 106300, MCZ 29639, UIMNH 25047, 25049, USNM 114551; Malinaltepec, ZMB 34351, 34353. _Oaxaca_: 2.5 km. N of La Soledad, KU 58061; San Lucas Camotlan, UIMNH 3201, USNM 123700-1; Vista Hermosa, KU 64116-7, 64119, 68560 (tadpoles), 71344, 71717-8 (tadpoles), UMMZ 119604; 5 km. S of Yetla, KU 60045 (tadpoles); _7.5 km. S of Yetla_, KU 64118, 68556-7 (tadpoles), 68559 (tadpoles), 68561 (2 young), 68630 (skeleton), UMMZ 115514-5, 118863 (tadpoles); 9 km. S of Yetla, KU 68558 (tadpoles).

=Ptychohyla spinipollex= (Schmidt)

_Hyla euthysanota_, Dunn and Emlen, Proc. Acad. Nat. Sci. Philadelphia, 84:25, March 22, 1932.

_Hyla spinipollex_ Schmidt, Proc. Biol. Soc. Washington, 49:45-46, May 1, 1936 [Holotype.--MCZ 21300 from the mountains behind Ceiba, Depto. Atlantidad, Honduras; Raymond E. Stadelman collector]. Stuart, Misc. Publ. Mus. Zool. Univ. Michigan, 69:32-34, figs. 5-6, June 12, 1948; Contr. Lab. Vert. Biol. Univ. Michigan, 45:22, 52, 54, 57, May, 1950; Proc. Biol. Soc. Washington, 67:169, August 5, 1954.

_Ptychohyla spinipollex_, Stuart, Contr. Lab. Vert. Biol. Univ. Michigan, 68:48, November, 1954. Duellman, Univ. Kansas Publ. Mus. Nat. Hist., 13:351, April 27, 1961.

_Diagnosis._--Rostral keel present; snout in lateral profile rounded above; eyelid nearly as wide as interorbital region; flanks white with brown spots; belly spotted; nuptial spines pointed and moderate in size.

_Description._--The following description is based on KU 58054 from Finca Los Alpes, Depto. Alta Verapaz, Guatemala (Pl. 15). Adult male having a snout-vent length of 37.7 mm.; tibia length, 18.2 mm.; tibia length/snout-vent length, 48.2 per cent; foot length, 15.8 mm.; head length, 11.7 mm.; head length/snout-vent length, 31.0 per cent; head width, 11.7 mm.; head width/snout-vent length, 31.0 per cent; diameter of eye, 3.6 mm.; diameter of tympanum, 1.9 mm.; tympanum/eye, 52.7 per cent. Snout in lateral profile nearly square, slightly rounded above, and in dorsal profile rounded with a pointed tip resulting from vertical rostral keel; canthus pronounced; loreal region barely concave; lips thick, rounded, and barely flaring; nostrils protuberant; internarial distance, 3.0 mm.; top of head flat; interorbital distance, 3.7 mm., about equal to width of eyelid, 3.6