Color (in alcohol) dark brown with irregular darker reticulations on dorsal surfaces of head, body, and limbs; flanks brown with small creamy white spots; posterior surfaces of thighs dark brown; chin creamy tan; belly grayish brown with cream-colored flecks; ventral surfaces of limbs pale brown; webbing on feet gray; small white spots in anal region. Color (in life) chocolate brown with darker brown reticulations and irregular blotches above; flanks brown with yellow spots; belly gray to grayish brown with faint cream-colored spots; iris a deep bronze color. _Variation._--In males the total number of vomerine teeth varies from 4 to 7. In many specimens the vomerine ridges are larger and more closely approximated medially than in the specimen described above. Females attain snout-vent lengths of 51 mm., have as many as 9 vomerine teeth, and have a proportionately larger tympanum than males. Some of the largest specimens of both sexes have indistinct cream-colored pustules scattered on the ventral surface of the forearm. Some individuals have nearly uniform grayish brown ventral surfaces; in others the chin, as well as the abdomen, is brown with cream-colored spots. The dorsal surfaces of some specimens are nearly uniform dark brown with no reticulations. In others the dorsum is paler brown with distinct darker mottling; in some of these there is little mottling laterally, so that there is the effect of an irregular, pale brown, dorsolateral stripe. _Tadpoles._--The tadpoles of this species were described by Rabb and Mosimann (1955). Tadpoles obtained from streams at 3.3 kilometers north and at 8.5 kilometers southeast of Zacualtipán, Hidalgo, are like those described by Rabb and Mosimann in having 2/3 tooth rows, peglike serrations on the beaks, and long rounded tails. The largest tadpole (KU 60078) has small hind legs, a body length of 22 mm., and a total length of 61 mm.