48 



b. Posterior maxillary teeth largest; scales 

 smooth. 



aa. Eye moderate or small; ventrals with 

 an obtuse lateral angle; maxillary teeth 



15 — 20; scales in 15 or 17 rows. . . 22. Siegonotus p. 114. 

 bb. Eye large; ventrals strongly keeled on 

 each side; maxillary teeth 8 — 10; scales 



in 13 or 15 rows 23. Dryocalannis p. 1 1 8. 



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

 O 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. 



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

 ,3. 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. 



<•<:. Maxillary teeth about 10; scales in 



17 rows 30. Oreocalamus p. 140. 



(^. No anterior temporal; scales in 15 rows. 



1. Nostril between two shields. 



X Supraocular absent; no praeocular; 



loreal absent 31. Idtopholis 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. Rhabdophiditan p. 145 



^.Praeocular small or absent 34. Psendorhahdiu»i -p. 146. 



00 Pupil vertically elliptic; scales in 17 or 



19 ""ows 35. Krachyorrhus p. 147. 



i) Oligodon dur/iciini.^ puUheirtDius and praefrontalis have the internasals. 

 fused with the praefrontals. 



