110 



VENOMS 



These are likewise divided into 

 two genera : — 



(c) Sistrurus. 



(d) Crotahis. 



(a) Ancistrodon. 



Usually with 9 shields on the 

 head, or internasals and praefrou- 

 tals broken up into scales. Body 

 cylindrical ; scales smooth or 

 keeled, with apical pits. Tail 

 moderate or short ; subcandals 

 single or in '2 rows. 



(1) A.piscivonts (Water Viper, 

 or Cotton-moutli ; fig. (J8). — Snout 

 rounded, soft above. Scales on 

 the body strongly keeled, in '25 

 (rarely 27) rows ; IHO — 147 ven- 

 trals ; 38—51 subcandals, all single 

 or the posterior divided. 



Colour pale reddish-brown to 

 dark Ijrovvn above, with more or 

 less distinct dark brown cross- 

 bands, or with alternating 

 C-shaped dark markings each en- 

 closing a central spot. Belly dull 

 yellow spotted with black, or al- 

 most l)lack. 



Total length, 1,170 millimetres; 

 tail 200. 



Habitat : Eastern North 

 America, from North Carolina 

 and Indiana to Florida and Texas. 

 The Water Viper lives lor tlie most part in the vicinity of 



I 



