48 



4. Posterior maxillary teeth largest; scales 

 smooth. 



aa. Eye moderate or small ; ventrals with 

 an obtuse lateral angle; maxillary teeth 



!j 20; scales in 15 or 17 rows. . . 22. Stegonotus p. 114. 

 bb. Eye large; ventrals strongly keeled on 

 each side; maxillary teeth 8 10; scales 



in 13 or 15 rows 23. Dryocalamus p. 118. 



tt Head not distinct from neck; internasals distinct '). 

 Pupil round. 



1. Posterior maxillary teeth smallest; scales in 



15 rows 24. Tetralepis p. 120. 



2. Posterior maxillary teeth largest. 



a. Maxillary teeth 8 12; pterygoid toothed; 



scales in 15 21 rows 25. Simotes p. 121. 



b. Maxillary teeth 6 8; pterygoid toothless; 



scales in 15 or 17 rows 26. Oligodon ') p. 127. 



3. Maxillary teeth subequal. 



a. Anterior temporal present. 



a.. Praeocular absent, scales in 15 rows. 27. Elapoides p. 134. 

 @. Praeocular present. 



aa. Maxillary teeth about 18; scales in 



15 or 17 rows 28. Hydrablabes p. 135. 



bb. Maxillary teeth 15 30; scales in 



13 or 15 rows 29. Ablabes p. 137. 



cc. Maxillary teeth about 10; scales in 



17 rows 30. Oreocalamus p. 140. 



b. No anterior temporal; scales in 15 rows. 



1. Nostril between two shields. 



X Supraocular absent; no praeocular; 



loreal absent 31. Idiopholis p. 141. 



XX Supraocular small; no praeocular; 



loreal present 32. Agrophis p. 143. 



2. Nostril in a single nasal. 



a. Praeocular large, reaching or nearly 



reaching the nasal 33. Rhabdophidium p. 145 



b. Praeocular small or absent 34. Pseudorhabdium p. 146. 



OO Ppil vertically elliptic; scales in 17 or 



19 rows 35. Brachyorrhus p. 147. 



i) Oligodon durheimi, pulcherrimus and praefrontalis have the internasals. 

 fused with the praefrontals. 



