fangs; with divided subcaudiils in all genera except Rhino* 



cheilus 



Thirty-six genera — 



Carphophis (1 species) 



Ahastor (1 species) 



Farancia (1 species) 



Diadophis (3 species) 



Rhadinaea (1 species) 



Heterodon (3 species) 



Opheodrys (2 species) 



Coluber (5 species) 



Drymohius (1 species) 



Drymarchon (1 species) 



Salvadora (3 species) 



Phyllorhynchus (2 species) 



Elaphe (10 species) 



Arizona (1 species) 



Pituophis (5 species) 



Lampropeltis (7 species) 



Stilosoma (1 species) 



Contia (1 species) 

 Sonora (5 species) 

 Ficimia (2 species) 

 Chilomeniscus (3 species) 

 Jslatrix (13 species) 

 Seminatrix (1 species) 

 Storeria (3 species) 

 Haldea (2 species) 

 Liodytes (1 species) 

 Thamnophis (9 species) 

 Tropidoclonion (1 species) 

 Conwphanes (1 species) 

 Oxyhelis (1 species) 

 Leptodeira (1 species) 

 Hvpsiglena (1 species) 

 Trimorphodon (3 species) 

 Tantilla (8 species) 

 Rhinocheilus (1 species) 



Cemophora (1 species) 



Family ELAPIDAE Coral Snakes 



Pupil round; front pair of upper teeth forming short, rigid, 

 poison fangs; native species with small eyes and body ringed 

 with red, yellow and black; with divided subcaudals 

 Two genera • — • Micrurus ( 1 species) 



TVLicrnroides (1 species) 



Family CROTALIDAE Pit-vipers 



Pupil vertical; with a deep pit between eye and nostril; with 

 a pair of long, hollow, poison fangs in front part of roof of 

 mouth, folded against roof when not in use; with undivided 



subcaudals 

 Three genera 



Ag\istrodon (2 species) 

 Sistrurus (2 species) 

 Crotaliis (13 species) 



389 



