124 INTRODUCTION 



V. berus is the northern and V. aspis the southern 

 species, yet the latter is the only one found on the 

 French side of the Pyrenees (up to 7,250 feet), whilst 

 the former reappears in North- Western Spain and 

 Portugal at very low altitudes, even at sea-level. 

 V. ursinii is a mountain form in Italy (Abruzzi), in 

 France (Basses-Alpes), and in the Balkan Peninsula 

 (up to 6,800 feet); but it is restricted to the plain in 

 Lower Austria and Hungary, where V. berus occurs 

 only in the mountains. 



Only three species are entirely confined to Europe : 

 Coluber scalaris, Vipera ursinii, and V. aspis. 



Of the species which range outside Europe, the 

 following occur both in Western Asia and in North 

 Africa : 



Eryx jaculus, Tropidonotus natrix, Ccelopeltis mons- 

 pessulana, Vipera lebetina. 



In Western Asia and the North-East of Egypt : 

 Tropidonotus tessellatus, Zamenis dahlii. 



In Western Asia : 



Typhlops vermicularis, Zamenis gemonensis, Coluber 

 quatuorlineatus, C, dione, C. longissimus, C. leopardinus, 

 Coronella austriaca, Contia modesta, Tarbophis fallax, 

 T. iberus, Vipera renardi, V. berus, V. ammodytes, 

 Ancistrodon halys. 



In North Africa : 



Macroprotodon cucullatus. 



