242 



2. Anal entire; poison-gland extending 

 along each side of the anterior third of 

 the body; heart far posteriorly; scales ^ , 



in 13 rows 61. DoUophis p. 251. 



II. Maxillary not extending forwards beyond the 

 palatine. 



a. Poison-fangs followed by 4 — 6 grooved teeth; 

 head not distinct from neck; subcaudals in 

 two rows. 



1. Anterior maxillary and mandibular teeth 

 abruptly enlarged; nostril between two 



nasals; scales in 17 rows 62. GlypJiodoii p. 254. 



2. Maxillary and mandibular teeth gradually 

 decreasing in size. 



f No praeocular. 

 aa. Pupil round; nostril lietween two 

 nasals; internasals present; scales in 



15 or 17 rows 63. Toxicocalaniiis p. 255. 



hb. Pupil round ; nostril in a single nasal ; 



no internasals; scales in 13 rows . . 64. Ultrocalavms p. 258. 

 tt Praeocular present. 



1. Pupil vertically elliptic; nostril be- 

 tween two nasals; scales in 15 rows. 65. Apistocalannis p. 260. 



2. Pupil round; nostril in a single nasal; 



scales in 15 rows 66. Pseudapistocalanius p. 262. 



b. Poison-fangs followed by 7 — 15 small grooved ^ ck>-ik 

 teeth; head slightly distinct from neck; sub- 

 caudals in two rows. 



1. Pupil vertical ;"'no canthus rostralis; scales 



in 15 rows .^ 67. Pseucielaps p. 264. 



2. I'upil round; cantlius rostralis distinct: 



scales in 15 rows 68. Dieiiiciiia p. 266. 



<". Poison-fangs followed by i — 5 small teeth, 

 sometimes indistinctly grooved. 

 f Habit colubriform or elapiform. 



1. Scales in 17 — 23 rows; subcaudals in two 



rows or partly single 69. Psciidcrhis p. 268. 



2. Scales in 15 rows; subcaudals in two rows. 10. Micropcchis p. 270. 

 ft Habit viperiform; posterior subcaudals 



paired; end of tail compressed, ending in 



a long spine; scales in 21 or 23 rows. . 71. Acaiithophis p. 271. 



Terrestrial snakes; mostly viviparous. 



