102 THE WANDERINGS OF ANIMALS [ctt. 



one occurs from Marocco to the Caspian, another 

 from Himalayas to China, the third in the United 

 States. (3) Iguanidae or iguanas, basiliscs and 

 ' horned toads.' Essentially American, with the re- 

 markable occurrence of two genera in Madagascar 

 and one in the Fiji and Friendly Islands. Mada- 

 gascar presents no difficulty, since iguanas are known 

 from French and English Eocene, and their total 

 absence from Africa and India may be accounted for 

 by the inroad of the fierce carnivorous Varans, which, 

 too late for Madagascar, exterminated the chiefly 

 herbivorous iguanas. The Fijian Brachyloplms re- 

 mains a puzzle, but on the Galapagos, nearly 600 

 miles from America, live two kinds of antediluvian- 

 looking Iguanids, one of which, Amblyrhynchus, is 

 semi-marine, feeding upon algae. 



Strictly American are the families of Teijus and 

 Ameivas. 



SNAKES. 



The earliest remains date from the Lower Eocene 

 of Egypt, amongst them gigantic forms allied to 

 boas or pythons which are still found in all tropical 

 countries. The majority of the snakes belong to the 

 cosmopolitan Colubridae, which seem to have given 

 rise in divergent directions to the poisonous Elapinae 

 and to the equally poisonous Viperidae ; the latter 

 are naturally divided into vipers and pit- vipers. The 



