228 OPHIDIA. — HYDROPHID^. 



to bite, but otlier observations tend to prove that 

 this mildness must not be relied on. 



M. Per on saw the Marine Serpents gliding 

 gracefully along in great numbers on the sur- 

 face of the Indian Seas, waging destructive war- 

 fare on shoals of small herrings, which fled 

 precipitately into deeper water. In the stomachs 

 of some which he captured, he found small fishes 

 and various species of marine Crustacea. The 

 Serpents, in their turn, become the prey of 

 sharks, — a fact which at first seems remarkable, 

 when we consider the swift agility of the former 

 contrasted with the unwieldiness of the latter ; 

 but the naturalist accounts for the fact by sup- 

 posing that the prey is seized when asleep on 

 the surface. So sound are their slumbers as 

 they float on the waves, that a large ship may 

 pass close among them, without awaking them 

 by the surging of its prow, or by the voices of 

 its cvew. They swim and dive with equal facility ; 

 often at the very instant when the voyagers are 

 throwing their nets over the slippery reptiles, 

 they wdll disappear beneath the waves, diving 

 to a great depth, an-d remaining more than half 

 an hour without ascending to the surface, re- 

 appearing at length, at a very great distance from 

 the spot where they had been seen to descend. 



The salt water creeks and ditches on the shores 

 of India and the great islands are greatly infested 

 by the Sea-Snakes, and this is probably what 

 Cuvier means when he afiirms that the Chersydrus 

 inhabits the bottoms of rivers in Java ; for no 

 species inhabits fresh water. 



Mr. Gray observes of the geographical distribu- 

 tion of the Family, that of the forty-eight species 



