The relationships of this toad seem to be with _Bufo bocourti_ Brocchi, an inhabitant of pine and oak forests in the uplands of Chiapas and Guatemala. In _Bufo occidentalis_ the tympanum usually is indistinct and sometimes completely covered, and it is absent in _bocourti_. _Bufo occidentalis_ has a broader interorbital area and relatively shorter and more rounded parotid glands than _bocourti_. The tadpoles of the two species are nearly identical (see Stuart, 1943:12). ~Leptodactylus labialis~ (Cope) _Cystignathus labialis_ Cope, Proc. Amer. Philos. Soc., 17:90, 1877.--No type locality designated; type locality restricted to Potrero Viejo, Veracruz, México, by Smith and Taylor (1950a:350). _Leptodactylus labialis_, Brocchi, Mission Scientifique au Mexique et dans l'Amerique Centrale, pt. 3, sec. 2, livr. 1:20, 1881. Apatzingán (26); Capirio (5); Cofradía (9); El Sabino (4); Lombardia; Río Tepalcatepec, 27 km. S of Apatzingán (2). In the Tepalcatepec Valley this frog reaches the northernmost known limit of its range in western México. Although the species is abundant in the valley, it apparently is absent from the coastal lowlands. In the Tepalcatepec Valley _Leptodactylus melanonotus_ seems to be more abundant than _labialis_. In the rainy season both species have been heard calling from the same ponds and flooded fields. There are only slight differences in size between the sexes; measurements of 20 males and eight females are, respectively: snout-vent length, 32.3-39.5 (35.1), 34.1-39.2 (37.2); tibia length, 14.3-17.0 (15.4), 14.9-16.8 (15.8); head width, 11.0-13.6 (12.0), 12.2-13.2 (12.6); head length, 12.8-15.1 (13.3), 12.8-14.6 (13.7). ~Leptodactylus melanonotus~ (Hallowell) _Cystignathus melanonotus_ Hallowell, Proc. Acad. Nat. Sci. Philadelphia, 12:485, 1861.--Nicaragua. Type locality restricted to Recero, Nicaragua, by Smith and Taylor (1950a:320). _Leptodactylus melanonotus_, Brocchi, Mission Scientifique au Mexique et dans l'Amerique Centrale, pt. 3, sec. 2, livr. 1:20, 1881. Apatzingán (103); Capirio; Charapendo (7); Coahuayana; Cofradía (10); El Sabino (21); La Playa (3); Lombardia (5); Maruata; Nueva Italia (7); Ostula (9); Playa Azul (11); Río Marquez, 10 km. S of Lombardia; Río Marquez, 13 km. SE of Nueva Italia (6); Río Tepalcatepec, 27 km. S of Apatzingán. This species is widespread in the lowlands of the state; it has been collected up to elevations of 1050 meters in the Tepalcatepec Valley. In the dry season individuals were discovered beneath rocks along streams and in damp arroyos; in the rainy season they were found wherever there was water. Males were heard calling from flooded fields, ditches, rocky streams, and small puddles. The call is a series of individual notes: "woink, woink, woink."