A Review of the Middle American Tree Frogs of the Genus Ptychohyla Part 4

_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).

[Ill.u.s.tration: PLATE 14 _Ptychohyla leonhardschultzei_ (KU 64117). 2.]

=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 G.o.dmani_, Ahl, Zool. Anz., 106:186, April 15, 1934.

_Hyla pinorum_ Taylor, Proc. Biol. Soc. Was.h.i.+ngton, 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. Was.h.i.+ngton, 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 p.r.o.nounced; 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. a.n.a.l opening near dorsal surface of thighs; short a.n.a.l 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 a.n.a.l 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 a.n.a.l 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; a.n.a.l 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 relations.h.i.+ps. 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).

[Ill.u.s.tration: PLATE 15 _Ptychohyla spinipollex_ (KU 58054). 2.]

=Ptychohyla spinipollex= (Schmidt)

_Hyla euthysanota_, Dunn and Emlen, Proc. Acad. Nat. Sci.

Philadelphia, 84:25, March 22, 1932.

_Hyla spinipollex_ Schmidt, Proc. Biol. Soc. Was.h.i.+ngton, 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.

Was.h.i.+ngton, 67:169, August 5, 1954.