Elaphe triaspis mutabilis (Cope).—The subspecies E. triaspis mutabilis is known from Alta Verapaz and E. triaspis triaspis from the Yucatán Peninsula, British Honduras, and Uaxactún in northern El Petén. Because of the much higher degree of resemblance between the faunas of southern El Petén and Alta Verapaz as compared with southern El Petén and Yucatán, E. triaspis mutabilis would be expected to occur in southern El Petén.
Ninia diademata nietoi Burger and Werler.—This snake is known from Tikal and from Alta Verapaz; it is a small cryptophile that probably occurs in southern El Petén.
Oxyrhophus petola aequifasciatus Werner.—This snake, which probably is conspecific with Oxyrhophus baileyi in southern Veracruz, México, is known from Tikal, British Honduras, and Alta Verapaz; it is expected in southern El Petén.
Pliocercus elapoides salvini Müller.—This species is widespread in the Atlantic lowlands of southern México and northern Central America; the subspecies P. elapoides salvini occurs in Alta Verapaz and probably in southern El Petén.
Rhadinaea decorata decorata (Günther).—This is another small cryptophile that is widespread on the Atlantic lowlands from México to Panamá; it definitely is expected at places like Chinajá in southern El Petén.
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.