THE PELAMYS BICOLOR. 183 



down to a point, and, though possessed of such perfect powers 

 of diving and swimming, nothing could induce it to enter the 

 water ; and as often as he threw it in, it returned in the manner 

 above described. 



Perhaps this singular piece of apparent stupidity may be 

 accounted for by the circumstance that this reptile has no 

 enemy whatever on shore, whereas at sea it must often fall 

 a prey to the numerous sharks. Hence, probably urged by a 

 fixed and hereditary instinct that the shore is its place of safety, 

 whatever the emergency may be, it there takes refuge. On a 

 comparison of this singular animal with the true iguanas, the 

 most striking and important discrepancy is in the form of the 

 head. Instead of the long pointed narrow muzzle of those 

 species, we have here a short obtusely truncated head, not so 

 long as it is broad ; the mouth consequently is capable of being 

 opened to only a very small extent. From this circumstance,* 

 and from the crest on its head, it has received the Latin name 

 of Amblyrhynchus cristatus. 



The serpent race, which thrives so abundantly in the tropical 

 forests and morasses, has also its marine representatives in the 

 Indian and Pacific Oceans, where more than fifty species of 

 Hydrophis, Pelamys, and Chersydra have been found. They 

 are distinguished from their terrestrial relations by the flattened 

 form of their tail, the planes of which being directed vertically 

 give it the properties of a powerful oar, in strik- 

 ing the water by lateral oscillations. These sea- 

 snakes always appear to prefer calms, swimming 

 on the still surface in an undulating manner, 

 never raising the head much from the surface, 

 or vaulting out of the water. They dive with 

 facility on the approach of danger, but do not 

 appear to be particularly timid. 



The Pelamys bicolor is very common from 



"Wafcsr-Siialce. 



India to Otaheite. In the seas of Mindoro and 

 Sooloo, Mr. Adams saw thousands swimming on the top of the 

 water, especially in eddies and tide-ways where the ripple 

 collects numerous fish and medusae, which principally constitute 

 their prey. Their tongue is white and forked, differing in 



o 



