390 COLUBRTD.5':. 



Eostral nearly as deep as broad, visible from above ; frontal 

 longer than broad, as long as its distance from the end of the 

 snout, shorter than the parietals ; one prae- and two postoculars ; 

 temporals 1 + 2; upper labials 7, third and fourth entering the 

 eye ; two pairs of chin-shields, anterior longest and in contact 

 with 3 labials. Scales in 15 rows ; vertebrals but feebly enlarged 

 and not broader tban long. Venti-als 212-225 ; anal entire ; 

 subcaudals single, 37-56. Uniform black or brown above ; upper 

 lip white ; lower parts white or pale brown. 



Total length 3 feet ; tail 4 inches. 



Hah. Assam. 



Genus NAIA, 



Laurenti, Syn. Eept. p. 90, 1768. 



Poison-fangs with a distinct groove anteriorly, followed by one 

 to three small solid teeth. Head distinct from neck, with large 

 shields ; no loreal. Eye rather small, with round pupil. Neck 

 dilatable. Body cylindrical ; scales disposed obliquely, smooth, in 

 15 or more rows. Tail moderate ; subcaudals in a single or double 

 row. 



Fig. 114.— Head of iVam hungarug. 



Distribution. Africa and Southern Asia. Oviparous. Terrestrial, 

 but often ascending trees, and readily entering the water. 



Six or seven species may be distinguished, of which three occur 

 in the Indian Region : — 



A. No large shields behind parietals. 



a. 23-27 scales across neck, 19-23 across 



middle of body ; subcaudals 49-7>% all in 



pairs N. trqnuUans, p. 391. 



b. 19-23 scales across neck, 17 across middle 



of body ; subcaudals 43-52, some of the [(Java & Borneo), 



anterior frequently single N. sjjut atria; Reinw. 



