bOLUiBElNA. 179 



*** Scales keeled ; loreal and prsefronfcal entering the 

 eye. 



t Scales not striated ; pupil round. 



A pair of inteniasals 19. AmpMardis, p. 290. 



A single internasal 20. Haldea, p. 290. 



tt Scales striated ; pupil subelliptic. 



A pair of internasals 21. Streptophorus, p. 291. 



**** Scales smooth. 



t Loreal and prseocular present. 



Nostril an oblique slit between two nasals ; pupil round. 



23. Hydrablabes, p. 296. 



Nostril between two nasals ; pupil vertically subelliptic. 



24. TrachiscMum, p. 297. 



Nostril in a semidivided nasal ; pupil vertically subelliptic. 



25. Rhabdops, p. 300. 



tt No loreal ; a large semidivided nasal in contact 

 with a prseooular. 



Dorsal scales oblique 26. Plagiopholis, p. 301. 



ttt Loreal and prsefrontal entering the eye. 



MaxiUary 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 ; prseocular 

 present or absent. 



Maxillary teeth 20 to 22 ; pupil vertically subelliptic. 



29. Brachyorrhus, p. 305. 



(i. Maxillary bone not extending forwards beyond the 

 palatines ; scales keeled ; loreal and prsefrontal 

 entering the eye. 



Maxillary teeth about 10 ; scales striated ; a single proetrontal. 



22. Chersodromus, p. 295. 



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



30. Elapoides, p. 306. 



6. Labial shields not entering the nostril ; subcaudal shields 

 single. 



Scales keeled 31. Achalinus, p. 308. 



n2 



