Part 11

Although the type locality is stated to be Santa Efigenia on the Pacific slopes of the Sierra Madre de Chiapas in eastern Oaxaca, the type specimen probably came from the northern slopes of the mountains. All other known specimens are from the Gulf slopes and lowlands, and from several localities in Los Tuxtlas. Details concerning specimens from the isthmus and other parts of the range were given by Duellman (1958c:8).

Smith (1947:408) reported a specimen of Syrrhophus verruculatus Peters from San Lorenzo, Veracruz; he stated that this specimen (USNM 123530) could not be S. leprus, because it had a gray belly, nor S. cystignathoides, because of the dark and light dorsal coloration. Firschein (1954:57) in his review of the species of Syrrhophus in eastern Mexico referred the specimen to S. cystignathoides. The specimen is in poor condition. Nevertheless, specific determination is possible. Numerous specimens of S. leprus from Los Tuxtlas have gray bellies; some have heavier pigmentation than the specimen from San Lorenzo. In preservative the dorsum is dark brown with lighter mottling. There is little doubt that the specimen from San Lorenzo is a Syrrhophus leprus, an abundant and widespread species in the humid Gulf lowlands of southern Mexico, and not verruculatus, if this is a valid species (see Firschein, op. cit.:58), and not cystignathoides, a species known from San Luis Potosi southward to central Veracruz.

=Syrrhophus pipilans pipilans= Taylor

Oaxaca: Cerro Arenal; Cerro San Pedro; 6 km. N of Chivela; 14 km. W of Tehuantepec (2).

In the isthmian region this frog is known only from the Pacific slopes and the Plains of Tehuantepec. Males call from the ground and from trees to heights of about four meters. The call is a single, high, long "peep."

=Engystomops pustulosus= Cope

Oaxaca: Chivela; La Ventosa (3); Santo Domingo; Tapanatepec (14); Tehuantepec (61); Union Hidalgo (62). Veracruz: Acayucan; Cuatotolapam (7); 10 km. SE of Hueyapan (11).

Large congregations were breeding at Tehuantepec on July 5, at Tapanatepec on July 13, and at Hueyapan on July 24, 1956. The frogs were breeding in open ponds in scrub forest and savanna; none was found in the rainforest. Males call while floating on the water (Pl. 7, fig. 1); the call is a soft "do-ing, do-ing" with a rising tone on the last note. Numerous individual egg masses were along the bank of a pond near Tehuantepec; one large composite egg mass there had a surface area of about one square meter (Pl. 7, fig. 2). The large series from Union Hidalgo was obtained by digging specimens out of a dry sandy river bank in the dry season. Some of the individuals were buried to a depth of 25 centimeters.

In life individuals from the Pacific lowlands were dull brown and gray; those from Acayucan were dark chocolate brown to black with pink or red blotches, forearms, and dorsal stripe. Not all specimens from the Atlantic lowlands are so colored; individuals from Cordoba and Mirador, Veracruz, are like those from Tehuantepec.

=Leptodactylus labialis= Cope

Oaxaca: Agua Caliente; Chivela (2); Matias Romero (12); 33 km. N of Matias Romero (4); Mixtequilla; Santa Efigenia; Tapanatepec; Tehuantepec (38); Tolosita (2); 33 km. W of Zanatepec (49). Veracruz: Acayucan (3); Ciudad Aleman; Cuatotolapam (10); Hueyapan; La Oaxaquena (4); 38 km. SE of Jesus Carranza; 20 km. ENE of Jesus Carranza; Novillero (3); San Lorenzo (2).

Although Leptodactylus labialis does not appear to be so abundant as Leptodactylus melanonotus, the former was found throughout the lowlands of the isthmus. In the dry season individuals were found along streams, and in the rainy season breeding congregations were found in rain pools, marshes, ponds, and even small puddles. The call is a slow "wort, wort, wort." Males call beneath the water and from beneath rocks and from holes in the ground. The average snout-vent length of eight adult males is 37.2 mm. A completely metamorphosed juvenile obtained at Hueyapan on July 24, 1956, has a snout-vent length of 11 mm.

=Leptodactylus melanonotus= Hallowell

Oaxaca: Agua Caliente (25); Cerro Arenal (2); Cerro Quiengola (3); Cerro San Pedro (3); Chivela (2); Coyol; Juchitan; Matias Romero (11); Mixtequilla (2); Papaloapan (2); Salazar (9); Salina Cruz; 11 km. S of Santiago Chivela; Tapanatepec (17); Tehuantepec (176); Tolosita; Union Hidalgo; 27 km. W of Zanatepec (6). Veracruz: Acayucan; Cuatotolapam (9); Cosoleacaque; 20 km. ENE of Jesus Carranza (2); 20 km. SE of Minatitlan (2); Novillero; San Lorenzo (6).

This frog is abundant throughout the lowlands of the isthmus, where in the dry season individuals were found along streams and beneath rocks at a spring seepage. In the rainy season males were calling from nearly every bit of standing water. The call is a soft clicking sound resembling that made by striking two small stones together. The average snout-vent length of ten adult males is 41.8 mm. There is considerable variation in the extent of the yellowish brown glandular areas on the belly. Some have none, whereas others have a broad area on the chest, a band along the flanks, and a thin band across the lower abdomen. Individuals collected in the dry season vary in the same fashion as do those collected in the rainy season, at which time they were breeding. The glands are equally well-developed in adults of both sexes, and were present in some juveniles with snout-vent lengths of less than 20 mm. Apparently the development of the glands is not associated with maturity, sex, or size.

=Diaglena reticulata= Taylor

Oaxaca: Cerro Arenal; Chivela; Salina Cruz (26); San Antonio (3); Tehuantepec (2); 8.6 km. W of Tehuantepec (11); Zarzamora.

Breeding congregations of this rare frog were found 8.6 kilometers west of Tehuantepec on July 5, 1956, and at Salina Cruz on July 6, 1958. Both choruses took place immediately after torrential rains. In both instances the frogs were in and about open muddy pools in the scrub forest (Pl. 5, fig. 2); males called from the bank near the water, and clasping pairs were found only on land (Pl. 8, figs. 1-2). The call is a loud, nasal "braaa," two to three seconds in duration. Amplexus is axillary.

The dorsal ground color is light yellowish green tending towards olive on the head and fading to yellow on the flanks. The ventral surfaces, including the vocal sac, are white; the iris is golden and flecked with black. The present series agrees well with the description of reticulata (based on two specimens) given by Taylor (1942:60). A detailed analysis of variation, comparison with related species, and descriptions of tadpoles are reserved for a future report.

=Hyla baudini= Dumeril and Bibron

Oaxaca: Bisilana; Cerro Quiengola (2); Cerro San Pedro; Coyol; Matias Romero (12); Mixtequilla; Rio Sarabia (7); Salazar; San Antonio; 11 km. S of Santiago Chivela; Santo Domingo (3); Tapanatepec (2); Tehuantepec (23); Tolosita. Veracruz: Acayucan; Amatitlan; Ciudad Aleman (3); Cosamaloapan (2); Cuatotolapam (15); 10 km. SE of Hueyapan; 20 km. S of Jesus Carranza; 38 km. S of Jesus Carranza (2); 20 km. ENE of Jesus Carranza (4); La Oaxaquena (2); Minatitlan (2); Naranja (3); Novillero (9); Rio de las Playas (2); San Lorenzo (5); Tapalapan (2).

Commonly found on both sides of the isthmus, this large tree frog nearly always is associated with trees; it is not found in the savannas, although it breeds in savannas adjacent to rainforest. It appears to be somewhat more abundant in scrub forest than in rainforest. In the daytime individuals were found under the outer sheaths of banana plants, in the axils of leaves of elephant ears (Xanthosoma), in cavities in trees, and on shaded limbs in the forest. Recently metamorphosed individuals having snout-vent lengths slightly more than 20 mm. were found in the latter part of July.

=Hyla ebraccata= Cope

Oaxaca: Donaji (17); 43 km. N of Matias Romero (27); Sarabia (6); Tolosita (3); Ubero (17). Veracruz: Aquilera.

This small species was found only in forested areas, where calling males were on bushes and trees around rain pools. The call is a harsh squawk repeated at intervals of 15 to 20 seconds, followed by a minute or more of silence, and then repeated. Clasping pairs were found on bushes and in the water.

The dorsum bears a dark chocolate brown hour glass-shaped mark, which in some individuals is broken into a large mark posteriorly and a smaller triangular one on the head and nape. The dorsal ground color varies from pale cream or ivory to yellow or tan. The intensity of the dorsal pigmentation is subject to rather rapid change. The flanks, hands, and anterior part of the venter are lemon yellow; the feet, thighs, and posterior part of the venter are golden yellow. The dorsal surface of the shank is yellow to tan with chocolate brown bars or spots; the heel is pale yellow. There is a dark brown bar in the loreal region and a dark brown bar extending posteriorly from the eye to a point above the insertion of the forelimb. The iris is a copper color. The toes are completely webbed; the fingers, one-third webbed. There is a small axillary web that is evident when the forelimbs are at right angles to the body. Twenty males have an average snout-vent length of 28.1 mm.; three females, 35.3 mm. There are no nuptial tuberosities on the pollex of breeding males.

This species has been collected at Coyame and Catemaco in Los Tuxtlas and at various localities in Tabasco; it apparently ranges eastward from southern Veracruz, Mexico, in humid forests to El Peten, Guatemala.

=Hyla loquax= Gaige and Stuart