28 COLUBRID. 
Body compressed ; scales slightly oblique; usually a subocular 
below the preocular and loreal divided. 
145. Trimorphodon, p. 53. 
Body compressed ; scales straight; no suboculars, 
146. Lycognathus, p. 56. 
2. Seales of vertebral row enlarged. 
147. Trypanurgos, p. 58. 
_ B. Solid maxillary teeth subequal or gradually increasing in 
length; head more or less distinct from neck; pupil 
vertical. 
1. Scales more or less oblique, vertebral row more or less 
enlarged. 
Subcaudals in two rows........ 148. Dipsadomorphus, p. 59. 
Subcaudals single ..... SEs 149. Dipsadoboa, p. 81. 
2. Scales not oblique. 
a. Ventral shields strongly angulate laterally; scales 
strongly keeled .. 150. Rhinobothryum, p. 82. 
b. Ventrals rounded or obtusely angulate. 
a. Nostril between two nasals. 
* Body very slender, strongly compressed ;_ scales 
very narrow. 151. Himantodes, p. 83. 
** Body cylindrical or moderately compressed, 
tT Maxillary teeth gradually and feebly increasing 
in length ; posterior nasal concave. 
Body cylindrical or moderately compressed ; loreal not entering the 
DTG Shas: '<'s spe Re PRA 152. Leptodira, p. 88. 
Body compressed; loreal entering the eye. 
153. Chametortus, p. 98. 
tt Maxillary teeth equal; body cylindrical or 
feebly compressed. 
Anterior mandibular teeth longest. 
154, Oxyrhopus, p. 99. 
Mandibular teeth subequal; rostral shield with sharp horizontal 
|, eee e et Cr 155. Rhinostoma, p. 114, 
f. Nasal entire or semidivided ; body cylindrical. 
* Scales with apical pits. 
+ Maxillary teeth 10 to 18, subequal. 
Mandibular teeth subequal; eye large. 
156. Thamnodynastes, p. 115, 
Anterior mandibular teeth longest ; eye moderate. 
157, Tachymenis, p. 117. 
