In the rain forests of southern Veracruz, Hyla phaeota cyanosticta breeds in pools in the forks of trees, depressions in logs and in pools on the ground. The breeding call consists of two rasping squawks uttered close together (occasionally one note), followed by a silent interval of 30 seconds or longer. There is probably no well-defined breeding period. The egg mass is a surface film in which each egg is surrounded by one envelope. In the laboratory, hatching occurred in stages 19 and 20, about 24 hours after fertilization. The oral disc appeared in stage 23 and was fully developed by stage 27. There is a median gap in the upper papillary border and the third lower tooth row is usually shorter than the other tooth rows. The labial tooth formula is 2/3. Tadpoles in advanced developmental stages (36-41) are dark brown over the dorsum, sides and tail muscle when pigment granules in the me- lanophores are dispersed. The dorsal fin is well pigmented but the ventral body wall, eye ring, ventral edge of the tail muscle, base of the ventral fin and tail tip are mostly unpigmented. Maximum total length attained by laboratory-raised larvae was 44 mm in stage 41. Metamorphosis (stage 46) of laboratory specimens occurred in a minimum of 40 days after hatching. Newly transformed frogs were about 14 mm in snout vent length. They lacked the reticulations on the sides and the blue spots and dark markings on the thighs that are present in the adults. Larvae of H. p. cyanosticta and H. baudini from the Tuxtla region are similar in pigmentation and body form, but may be distinguished by differences in pigmentation of the ventral and lateral aspects of the tail muscle. The larvae of H. baudini from southern Vera- cruz differ from Yucatan baudini larvae in the structure of the dorsal fin, oral disc and anal tube. H. phaeota cyanosticta adults differ from some adult H. p. phaeota in having no postorbital processes and in breeding call. Smilisca, to which H. baudini and H. phaeota have been assigned by other authors, cannot be separated from Hyla on the basis of differences in the squamosal bone, depressor mandibulae muscle or presence of postorbital processes. In the summers of 1962 and 1964 I collected several tadpoles and adults (Fig. 1, frontispiece) of the treefrog Hyla phaeota cyanosticta in the Tuxtla region of southern Veracruz. One of the adults was a female that lived 15 months in captivity, and in that interval laid nine egg masses. Since the tadpole of H. phaeota cyanosticta is presently unknown, representative developmental stages from these egg masses were preserved in order to obtain a complete series, and to verify iden- tification of larvae collected from natural breeding sites. Life history and anatomical information in this report are based on these speci- mens, together with observations on the breeding activity of H. p. cyanosticta in the Catemaco basin of the Tuxtla region. The specimens are in the collection of the Arlington State College Vertebrate Museum. HABITAT AND BREEDING SITES. The Sierra de Tuxtla is a volcanic range