COLUBRIN.&. 3 



* Head distinct from neck ; eye large or rather large ; 

 body much elongate ; scales with apical pits. 



f Scales forming longitudinal series. 



Maxillary teeth 12 to 20 54. Zamenis, I. p. 379. 



Maxillary teeth 25 to 30 ; scales of vertebral row enlarged. 



56. Xenelaphis, II. p. 7. 

 Maxillary teeth 22 to 32 ; no suboculars. 



57. Drymobius, II. p. 8. 



ft Scales disposed obliquely, at least on the anterior 

 part of the body ; maxillary teeth 20 to 25. 



Lateral scales as long as dorsals. 66. Chlorophis, II. p. 91. 



Lateral scales much shorter than dorsals. 



70. Thrasops, II. p. 104. 



** Head not or but slightly distinct from neck; eye 

 moderate or small. 



t Internasals, nasals, and pra-frontals distinct, 

 t Subcaudals in two rows. 



Maxillary teeth 14 to 24 ; scales without pits ; tail conical. 



81. Rhadinaea, II. p. 160. 



Maxillary teeth 13 to 16 ; scales without pits ; usually one or more 

 suboculars ; tail long, thick throughout, ending obtusely. 



82. Urotheca, II. p. 180. 

 Maxillary teeth 12 to 20, posterior not compressed ; scales with 



apical pits ; no suboculars . . 88. Coronella, II. p. 188. 



Maxillary teeth 8 to 11, posterior not compressed ; snout strongly 

 projecting 91. Cemophora, II. p. 213. 



Maxillary teeth 8 to 12, posterior compressed ; snout more or less 

 projecting 92. Simotes. II. p. 214. 



JJ Subcaudals single ; snout strongly projecting ; 

 maxillary teeth 16 to 19. 



90. Rhinochilus, II. p. 212. 



tt A single praefrontal ; two internasals. 

 Eye small ; nostril between two nasals. 



83. Trimetopon, II. p. 184. 



Eye very small ; nasal single . . 84. Hydromorphus, II. p. 185. 



ttt A single internasal ; two proefrontals ; nasal 

 semidivided, in contact with the praeocular. 



Eye rather small ; scales as broad as long. 



85. Dimades, II. p. 185. 



Eye very small 86. Hydrope, II. p. 186. 



B2 



