COLTJBRIUJE. 5 



6. Posterior maxillary teeth separated from the rest by an 

 interspace. 



Scales with apical pits 95. Leptocalamus, II. p. 249. 



Scales without pits 96. Arrhyton, II. p. 251. 



D. Maxillary teeth equal or nearly so, or posterior decreasing in 

 size. 



1. Scales with apical pits. 



o. Longitudinal series of scales in even numbers ; eye large : 

 no suboculars .... 59. Spilotes. II. p. 23. 



6. Longitudinal series of scales in odd numbers. 



a. Head distinct from neck ; eye moderate or large ; body 

 usually much elongate. 



* Maxillary teeth nearly equal ; scales forming straight 



longitudinal series. 



Nasals distinct, not fused with the loreal ; ventrals rounded or more 

 or less distinctly angulate laterally. 



60. Coluber, II. p. 24. 



Nasal single, fused with the loreal, in contact with the praeocular ; 

 ventrals sharply angulate laterally. 



61. Synchalinus, II. p. 70. 



Nasals distinct ; ventrals and subcaudals with a suture-like lateral 

 keel and a notch on each side corresponding to the keel. 



62. Gonyophis, II. p. 70. 



** Posterior maxillary teeth decreasing in size ; scales 

 narrow and oblique; ventrals and subcaudals with 

 a suture-like lateral keel and a notch on each side 

 corresponding to the keel. 



65. Dendrelaphis, II. p. 87. 



/3. Head not or but slightly distinct from neck. 



* Maxillary teeth equal or subequal. 



Snout cuneiform ; rostral shield with obtuse horizontal keel. 



97. Simophis, II. p. 253. 



Snout beak-shaped, hooked; rostral shield with sharp horizontal 

 keel 98. Scaphiophis, II. p. 254. 



Snout obtuse or pointed ; nasal distinct from the labials. 



99. Contia, II. p. 255. 



Snout pointed ; rostral in contact with or approaching the frontal ; 

 nasal fused with the first labial. 



100. Picimia, II. p. 270. 



