46 



pitless vipers, as supra-oculars, pasals, labials, 

 etc., can generally be made out. 

 Unfortunately for the strict definition of our 

 Group IV, three of the species have nearly 

 normally shielded heads like the snakes in 

 Group III. One of these three is the 

 common Himalayan Viper. But as these 

 three are vipers and so naturally come into 

 Group IV, and can be readily recognised by 

 the loreal pit, I have not thought it necessary 

 to make another group. 



Scales — Generally about 21 — 25. One species has 29. 



Ventrals — Less than 200. 



Colouring — Pit- vipers are all green or brown with 

 various black markings. 



Habitat — Hilly or mountainous regions. The Hima- 

 layas, Ghats, South Indian ranges and Ceylon. 



THE CO>[MON VIPER OR BAMBOO SNAKE 

 {Lachesis gramineus). 



Length — Grows to 3 or 3J feet. 



Shape — As above. 



Head shields — A scaly head. But there is a single supra- 

 ocular and 9 to 12 labials, also a single nasal. 



Scales — 21, keeled. Posteriorly only 15. 



Colour — Usually vivid foliage-green. More rarely 

 yellowish or brown, sometimes streaked with 

 black. Usually a well defined white or yellow 

 flank line. 

 Belly : whitish or greenish, uniform or indistinct- 

 ly mottled. 



Habitat — Much the commonest and most widely distri- 

 buted of the pit- vipers. Found in the Hima- 

 layas, E. and W. Ghats, Nilgiris and other hills. 



