CLASSIFICATION OF VERTEBRATA 29- 



a. Aglypha. Teeth solid, not grooved. Cosmopolitan. 

 Tropidonotus, Zamenis, Coluber, Dendrophis, Coronella, 



Calamaria, Dasypeltis (Ehachiodon), etc. 

 &. OpistJioglypha. One or more of the posterior maxillary 

 teeth are grooved. Slightly poisonous. Cosmopolitan. 



Psammophis, Dryophis, etc. Hypsirhina (entirely 



aquatic and viviparous). 



c. Proteroglypha. Anterior maxillary teeth grooved or 

 perforated. Very poisonous. 



Tail cylindrical, terrestrial ; mostly viviparous, cosmopoli- 

 tan, warmer zones. 



Elaps, Naja, Bungarus, Sepedon, Dendraspis, etc. 

 Tail laterally compressed ; aquatic, viviparous. 

 Indian and Pacific coasts. Hydrophis, etc. 



Distira, landlocked in fresh-water lake of Luzon. 

 Amblycephalidae. Like the Colubridae, hut pterygoid short 

 and not reaching quadrate ; supratemporal vestigial. Aglyph- 

 odont. Neotropical and Indo-Malayan. 



Amblycephalus, etc. 



Viperidae. With movable supratemporal, pterygoid articu- 

 lating with quadrate. Maxilla short and vertically erectile 

 to the pterygoid. No coronoid. Prefrontal not in contact with 

 nasal. Viviparous, excluding Atractaspis. Very poisonous. 

 Cosmopolitan, excluding Madagascar and Australia. 



Viper inae. Maxilla solid. No pit on the side of the 

 snout. Europe, Asia, Africa. 



Vipera, Cerastes, Echis, Atractaspis, etc. 

 Crotalinae. Maxilla hollowed out above, receiving the- 

 deep, externally visible pit. 



Ancistrodon. Asia, America. 

 Lachesis. SE. Asia and S. America. 

 Crotalus. America. 



