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