bipsadomoephiNjB. 27 



Synopsis of the Genera. 



I. Hypapophyses present throughout the vertebral column, 



represented on the posterior dorsal vertebrse by a more or 

 less developed crest or tubercle projecting below the 

 condyle. 



A. Solid maxillary teeth equal or subequal. 



1. Pupil round; body cylindrical ; scales smooth. 



Mandibular teeth subequal ; scales without pits. 



134. Geodipsas, p. 32. 



Anterior mandibular teeth strongly enlarged ; scales without pits ; 

 subcaudals single 135. Hologerrhnm, p. 33. 



Anterior mandibular teeth longest ; scales with apical pits. 



136. Ithycyphus, p. 34. 



2. Pupil vertical. 



a. Eye moderate ; body cylindrical. 



Snout ending in a long scaly appendage ; scales keeled. 



137. Langaha, p. 35. 



Snout without appendage ; scales strongly keeled. 



138. AUuaudina, p. 38. 



Snout without appendage ; scales smooth ; a series of suboculars. 



139. Eteirodipsas, p. 38. 



b. Eye large ; body compressed ; scales smooth. 



140. StenopMs, p. 39. 



B. Solid maxillary teeth very unequal ; anterior mandibular 



teeth strongly enlarged ; pupil vertical. 



Body compressed ; scales smooth ; tail long. 



141. Lycodryas, p. 44. 



Body cylindrical ; scales smooth or obtusely keeled ; tail moderate, 

 with single subcaudals ; nostril between nasal and supranasal. 



142. Pythonodipsas, p. 45. 



Body cylindrical ; scales smooth ; tail short, with single subcaudals. 



143. DitypopMs, p. 46. 



II. Hypapophyses absent in the posterior dorsal vertebrae. 



A. Solid maxillary teeth gradually decreasing in length, the 

 anterior much longer than the posterior; head distinct 

 from neck ; pupil vertical. 



1. Vertebral scales not enlarged. 

 Body cylindrical or slightly compressed ; scales oblique ; no sub- 

 oculars 144. Tarbophis, p. 47. 



