28 



COLTJBRID^. 



Body compressed ; scales sHghtly oblique j usually a subocular 

 below the preeocular and loreal divided. I 



145. Trimorphodon, p. 53. 



Body compressed ; scales straight ; no suboculars. ■ ^ 



146. Lycognathus, p. 56. ' 5 "- 



2. Scales of vertebral row enlarged. ^ 

 147. Trypamirgos, 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 149. Dipsadoboa, p. 81. 



2. Scales not oblique. "^ 



a. Ventral shields strongly angulate laterally; scales 

 — ■ strongly keeled . . 150. Ehinobothryum, p. 82. / " 



6. Ventrals rounded or obtusely angulate. 



a. Nostril between two nasals. 



— - * Body very slender, strongly compressed ; scales 

 very narrow . 161. Himantodes, p. 83. 



** Body cylindrical or moderately compressed. 



t MaxUlary teeth gradually and feebly increasing 

 in length ; posterior nasal concave. 



Body cylindrical or moderately compressed ; loreal not entering the 



— eye ". 152. Leptodira, p. 88. 



Body compressed ; loreal entering the eyeT 



163. ChamsBtortus, 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 

 edge 155. Rhinostoma, p. 114. 



/3. Nasal entire or semidivided ; body cylindrical. 

 * Scales with apical pits. 



t Maxillary teeth 10 to 18, subequal. 

 — . Mandibular teeth subequal ; eye large. 



156. Thamnodynastes, p. 115. 

 —Anterior mandibular teeth longest ; eye moderate. 



157. lachjnneiiis, p. 117. 



rrrrr 



