coltibkinJi. 179 



*** Scales keeled ; loreal and pra3frontal enteriag the 

 eye. 



t Scales not striated ; pupil round. 



A pair of intcriiasals 19. Amphiardis, p. 290. 



A single iuternasal 20. Haldea, p. 290. ^•^^ 



ft Scales striated ; pupil subelliptic. 



A pair of internasals 21. Streptophorus, p. 291. ^ •*' ^' 



**** Scales smooth. 



t Loreal and praeocular present. 



Nostril an oblique slit between two nasals ; pupil round. 



23. Hydrablabes, p. 296. ■ ' 



Nostril between two nasals ; pupil vertically subeUiptic. 



24. Trachischium, p. 297. 



Nostril in a semidivided nasal ; pupil vertically subelliptic. 



25. Rhabdops, p. 300. - 



ft No loreal ; a large semidivided nasal in contact 

 with a prseocular. 



Dorsal scales oblique 26. Plagiopholis, p. 301. 



ttt Loreal and prsefrontal entering the eye. 



Maxillary teeth 30 to 35 ; pupil vertically subelliptic. 



27. Oxyrhabdium, p. 302. 



Maxillary teeth 20 to 25 ; pupil round. , 



28. Xylophis, p. 303. >»^»*^*-*- 



tttt No loreal ; a single small nasal ; prteocular 

 present or absent. 



Maxillary teeth 20 to 22 ; pupil vertically subelliptic. 



29. Brachyorrhus, p. 305. ' " ' 



f?. Maxillary bone not extending forwards beyond the 

 palatines ; scales keeled ; loreal and praefrontal 

 entering the eye. 



Maxillary teeth about 10 ; scales striated ; a single pra^f rental. 



22. Chersodromus, p. 295. 



Maxillary teeth about 20 ; scales not striated ; a pair of prefrontals. 



30. Elapoides, p. 306. 



6. Labial shields not entering the nostril ; subcaudal shields 

 s'ngle. 



Scales keeled 31. Achalinus, p. 308. 



n2 



