2 REPTILES. 



Synopsis of the Families. 



Sub -order I. Viperine. Jmvs weak; upper toothless, with fangs 

 in front; lower toothed. Ventral shields broad, hand-like. 

 Head large behind ; crown fiat, generally covered ivith scales, 

 rarely with shields. Hinder limbs not developed. Eyes lateral. 

 Nostrils apical, lateral. 



1. Crotalid^. Face with a large pit on each side, placed be- 



tween the eye and the nostril. 



2. ViPERiD^. Face without any pit on the cheek. 



Sub-order I. Colubrine. Jaivs strong, both toothed, sometimes with 

 some fangs in front or grooved teeth behind. Head moderate or 

 indistinct ; croivn often covered with regular shields. 



Sect. I. Belly covered with narroiv, elongate shields or scales, nearly 



resembling those of the back. 



3. Hydride. Vent without any spurs like rudimentary feet. 



Nostrils superior, valvular. Eyes superior ; pupil round. Tail 

 often compressed. Belly covered with narrow shields or with 

 scales like those of the back, the central series sometimes 

 united together in pairs, forming a narrow 6-sided shield. 



4, BoiD^. Vent with spur-like rudimentary feet on each side. 



Eyes and nostrils lateral. Tail conical, generally prehensile. 

 Ventral shield narrow, transverse, band-like. 



Sect. II. Belly covered with broad, band-like shields. Vent tvithont 

 any spur-like feet. Tail conical, tapering. 



5. CoLUBRiD^. Nostrils apical, lateral, open. Head generally 

 shielded. 



