16 



Head shields — The nasals are contiguous, there being no 

 internasals. The supra- and post-oculars are 

 confluent. No temporals. Upper labials 

 four. 



Scales — 17, round and pohshed, 



Ventrah — 193 to 234. Very narrow. Sub-caudals 6— 1 1. 



Colour — Yellowish ; or brown above usuall}^ with numer- 

 ous transverse series of small, yellow black- 

 edo^ed ocelli. Belly brown with large yellow 

 spots or cross-bands ; or yellow mottled or 

 blotched. 



Habitat — These small burrowing snakes are fairly com- 

 mon in the hills of Southern India at a height 

 from 2,000 to 4,500 feet. 



RUSSELL'S WATER SNAKE {Cerberus rhynchops). 



This snake is about the commonest and most typical 

 of the river snakes. 



The river snakes live in rivers and estuaries and rarely 

 come to land. 



Length^Grows to 3 feet or more. Tail one-fifth of 

 length. 



Shape — Head : small, not very distinct from neck. Cleft 

 of mouth turned up behind the eye. 



Body : cylindrical. 



Tail : moderate, slightly compressed. 



Eye : small, pupil vertically elliptic. 



Nostrils small, placed on the top of the head 



and valvular. This feature is characteristic 



of the river snakes. 



Head shields — The head is shielded but irregularly (as 

 in all the river snakes). 

 The frontal may be brok^en up into small shields. 



