6io 



OPHIDIA 



CHAP. 



T. mperiiuis. — The scales are strongly keeled and form twenty- 

 one to twenty-three longitudinal rows. The third and fourth labials 

 border the eye. The anal shield is divided. The eyes and nostrils 

 are directed upwards instead of sidewards, in adaptation to the 

 essentially aquatic habits of this species, which lives upon fishes 

 and Amphibia. The general colour is grey to reddish brown, 

 with a black zigzag band along the back and a lateral series of 

 black, yellow-eyed spots. The belly is yellow or red, checkered 

 with black. 



The Viperine Snake bears a general resemblance to the 

 common viper. It inhabits France, Italy, Spain and Portugal, 

 and Morocco. Very large specimens attain a length of nearly 

 3 feet, but the ordinary size of adults is 2 feet^ This snake 

 spends most of its time in the water, but it is often found on 



Fig. 160. — Tropidonotus sirtalis. x L 



land, 1)asking on the top of a low wall or on a low 'shrub. It 

 is exceedingly common in Spain and Portugal, where it inhabits 

 almost every ditch, any standing water or slow river. In the 

 Alemtejo, when during the rainless and hot summer the small 



