VIPER A 221 



Asia, and Africa ; the Crotalince are Asiatic (one 

 species extending its range into a small part of 

 South-Eastern Europe) and American. 



Genus VIPERA, Laurenti 



Head distinct from neck, covered with small 

 shields or scales, with or without distinct frontal and 

 parietal shields ; eye moderate or small, with vertical 

 pupil, separated from the labial shields by scales ; 

 nasal separated from the rostral by a naso-rostral. 

 Body short. Scales keeled, with apical pits. Tail 

 short. 



Of the eleven species of this genus, six are found in 

 Europe ; two inhabit South-Western Asia, one the 

 Indo-Malay region, and two Eastern Africa. 



The distinction of the European species is one of 

 considerable difficulty, owing to their close relation- 

 ship and the presence of intermediate forms connect- 

 ing them. Matters being so, it seems curious that 

 the Common Adder should have been regarded by 

 so many authors as generically distinct from the 

 Asp Viper, under the name of Pelias berus. It is 

 highly probable that hybrids are produced in those 

 districts where two species coexist, as in some parts 

 of France, North Italy, and Austria. 



21. Vipera ursinii, Bonaparte 

 Orsini's Viper 

 Form. — Short and stout. Snout obtusely pointed, 

 flat above or with the canthus slightly raised. Eye 



