During both visits to Chinajá this large toad was breeding in a small permanent pond in the camp. During the day the toads took refuge in crevices beneath the buildings or beneath large boulders by the pond. At dusk from four to ten males congregated at the pond and called. Tadpoles of this species were in the pond in March and in July. One juvenile was found beneath a rock in the forest, and another was on the forest floor by day. The natives' name for this species and the following one is _sapo_. =Bufo valliceps valliceps= Wiegmann Chinajá, 52; Río San Román, 8; Sayaxché, 2; Toocog, 1. This is one of the most abundant, or at least conspicuous, amphibians inhabiting the forest. Breeding congregations were found on February 24, March 2, March 11, and June 27. At these times the toads were congregated at temporary ponds in the forest or along small sluggish streams. Throughout the duration of both visits to Chinajá individual males called almost nightly at the permanent pond at the camp. The variation in snout-vent length of 20 males selected at random is 56.7 to 72.5 mm. (average, 64.8 mm.). Two adult females have snout-vent lengths of 80.4 and 87.6 mm. In all specimens the parotid glands are somewhat elongated and not rounded as in _Bufo valliceps wilsoni_ (see Baylor and Stuart, 1961:199). My observations on the condition of the cranial crests of the toads in El Petén agree with the findings of Baylor and Stuart (_op. cit._:198) in that hypertrophied crests are usual in large females. In the shape of the parotids and nature of the cranial crests the specimens from El Petén are like those from the Isthmus of Tehuantepec in México. As I pointed out (1960:53), the validity of the subspecies _Bufo valliceps macrocristatus_, described from northern Chiapas by Firschein and Smith (1957:219) and supposedly characterized by hypertrophied cranial crests, is highly doubtful. In the toads from El Petén the greatest variation is in coloration. The dorsal ground-color varies from orange and rusty tan to brown, yellowish tan, and pale gray. In some individuals the flanks and dorsum are one continuous color, whereas in others a distinct dorsolateral pale colored band separates the dorsal color from dark brown flanks. In some individuals the venter is uniform cream color, in others it bears a few scattered black spots, and in still others there are many spots, some of which are fused to form a black blotch on the chest. In breeding males the vocal sac is orange tan. All specimens have a coppery red iris. Aside from the breeding congregations, active toads were found on the forest floor at night; a few were there by day. Some individuals were beneath logs during the day. =Eleutherodactylus rostralis= (Werner) Chinajá, 10.