=_Scaphiodontophis annulatus_= (Duméril and Bibron).--Three subspecies of _Scaphiodontophis annulatus_ are recognized in northern Central America: _S. annulatus annulatus_ from Alta Verapaz, _S. annulatus hondurensis_ from northern Honduras, and _S. annulatus carpicinctus_ from Piedras Negras and Tikal in El Petén and from British Honduras. This rare and highly variable species probably occurs in southern El Petén. =_Tantilla schistosa schistosa_= (Bocourt).--This widespread species in Central America is known from several localities in Alta Verapaz and almost certainly occurs in southern El Petén. =_Tropidodipsas sartori sartori_= Cope.--This fossorial species has been collected in northern El Petén and in Alta Verapaz. The natives at Chinajá described to me a _coral_ having orange rings on a black body that likely was this species. =_Micrurus elegans veraepacis_= Schmidt.--This species has been collected at various localities in Alta Verapaz and in Chiapas, inhabits areas like those in southern El Petén, and probably occurs there. SUMMARY A study of the amphibians and reptiles in the rainforests of southern El Petén, Guatemala, reveals the presence of 78 species; an additional 13 species probably occur there. In this tropical area having a high amount of rainfall most of the species of amphibians and reptiles have extensive ranges in the wet forests on the Atlantic lowlands of southern México and northern Central America; some species that more frequently are found in sub-humid forests also occur. Ecologically the fauna is divided into five major habitats--aquatic, aquatic margin, fossorial, terrestrial, and arboreal. Forty-two per cent of the 78 species are wholly or partly arboreal. The fauna is most closely related to that in Alta Verapaz, Guatemala, but includes many species that occur in the Tikal-Uaxactún area in northeastern Guatemala. _Eleutherodactylus rostralis_ (Werner) and _E. rhodopis_ (Cope) are redefined and their relationships are suggested. The color phases of _Dryadophis melanolomus laevis_ and _D. m. alternatus_ are discussed; _Dryadophis sanguiventris_ Taylor is synonymized with _Dryadophis melanolomus alternatus_ (Bocourt). The breeding habits, eggs, and tadpoles of the hylid frogs _Hyla ebraccata_ and _Phyllomedusa callidryas taylori_ are described, as are the eggs and juveniles of _Laemanctus deborrei_. LITERATURE CITED BAYLOR, E. R. AND STUART, L. C. 1961. A new race of _Bufo valliceps_ from Guatemala. Proc. Biol. Soc. Washington, 74:195-202, August 11. BOGERT, C. M. AND OLIVER, J. A. 1945. A preliminary analysis of the herpetofauna of Sonora. Bull. Amer. Mus. Nat. Hist., 83:297-426, March 30. BROCCHI, P. 1881-1883 Étude des batraciens de l'Amerique Centrale. Mission scientifique au Mexique. Paris, Imprimerie Nationale, 3 (2):1-122, pls. 1-21.