30 COLUBBID^. 



D. Solid maxillary teeth unequal, the middle ones the longest. 



1. Solid maxillary teeth forming an uninterrupted series; 



pupil round. 

 Maxillary teeth 10 or 11, gradually decreasing in size in front and 

 behind 169. DromopMs, p. 149. 



MaxiUary teeth 14, middle ones much enlarged. 



170. Taphrometopon, p. 151. 



2. Longest solid maxillary teeth foUowed by a gap. 

 a. Pupil round ; scales with apical pits. 



Loreal in contact with the prseocular. 



171. PsammopMs, p. 152. 



Loreal separated from the prseocular by the praefrontal. 



172. MimopMs, p. 171. 



h. Pupil vertically subeUiptic. 



Eye rather large ; scales without apical pits, 



173. Psammodynastes, p. 172. 



Eye rather small ; scales with apical pits. 



174. Macroprotodon, p. 175. 



c. PupU horizontal ; scales very oblique, with apical pits. 



175. DryopMs, p. 177. 



E. Solid maxUlary teeth subequal or increasing in length to 

 the last ; head not or but slightly distinct from neck ; 

 pupil round ; scales without apical pits. 



1. Suboaudals in two rows. 



a. Solid maxillary teeth 10 to 15, the grooved fangs 

 below or just behind the vertical of the posterior 

 border of the eye. 



a. Grooved maxillary teeth very large ; anterior 

 mandibular teeth longest. 



161. Conophis, p. 122. 



/3. Grooved maxillary teeth feebly or moderately 

 enlarged j mandibular teeth equal, 



* Internasals distinct from nasals ; two praefrontals, 



t Loreal present. 



Eye moderate ; tail moderate or long ; nostril between two nasals. 



181. Erythrolamprus, p. 199. 

 Eye small ; tail moderate ; nasal entire or semidivided. 



182. Hydrocalamus, p. 209. 

 Eye smaU ; tail short ; nostril between two nasals. 



183. ScolecopMs, p. 210, 



