122 INTRODUCTION 



A few words as to the salient characters of 

 the European fauna, which is a poor one as com- 

 pared with other parts of the world. The single 

 species of the genera Typhlops and Eryx must be 

 regarded as outposts from South-Western Asia ; the 

 single species of Ancistrodon, which extends from 

 Central Asia into a very small territory to the south- 

 east, is also an Asiatic type. The genera Tropido- 

 notus, Z amends t Coluber, Coronella, and Contia, are 

 characteristic of the Northern Hemisphere, and the 

 first three are, besides, equally well represented in 

 the Oriental region ; a few species of Tropidonotus are 

 also found in Africa and Madagascar. Ccelopeltis, 

 Macroprotodon, and Tarbophis are the northern out- 

 posts of an Afro- Indian group, although, with 

 the exception of the third, exclusively confined to 

 the circum-Mediterranean district. The genus Vipera 

 is also represented in East Africa and in Southern 

 Asia, but the species V. berus is essentially a northern 

 type, extending to the highest latitude reached by 

 any snake, and ranging all over Northern Asia to the 

 Amur and Sachalien. The same species reaches the 

 greatest altitude at which any snake has been observed 

 on the northern side of the Alps — viz., 9,000 feet. 



Of the twenty-eight species inhabiting Europe, 

 only two are generally distributed : Tropidonotus 

 natrix and Coronella austriaca. One is to be regarded 

 as a northern form, although occurring locally in the 

 south : Vipera berus. It is the reverse with Coluber 



