142 



WATER REPTILES OF THE PAST AND PRESENT 



One or two species only, the "Gila monsters," are reputed to be 

 venomous. 



There is but a single species of lizard now living which is in 

 any true sense aquatic in habit, the well-known sea-lizard of the 

 Galapagos Islands, scientiiically known as Amhlyrhync/ius crislatus. 

 It is a large lizard, with a short rounded head, a flat tail, and webbed 



Fig. 66. — Amblyrhynclms crislatus, the Galapagos sea-lizard. (From Brehm) 



feet. Its specific name is derived from the erect fringed crest 

 along its back and tail. Its habits arc best given in Darwin's 

 words: 



It is extremely common on all the islands throughout the group, and lives 

 exclusively on the rocky sea-beaches, being never found, at least I never saw 

 one, even ten yards inshore. It is a hideous looking creature, of a dirty black 

 color, stupid and sluggish in its movements. The usual length of a full-grown 

 one is about a yard, but there are some even four feet in length; a large one 

 weighed twenty pounds. The tails are flattened sideways, and all four feet 

 are partially webbed. They are occasionally seen some hundred yards from the 



