bo 
Or 
THE PRINCIPAL SPECIES OF POISONOUS SNAKES 
Habitat : South-east France (Basses-Alpes); Italy (Abruzzi) ; 
Istria; Mountains of Bosnia; Plains of Lower Austria; Hungary 
(environs of Buda-Pesth). 
Vipera berus (Common Viper, or Adder). 
Snout rounded, short and truncate; pupil vertically elongate ; 
vertical diameter of the eyes equal to or greater than the distance 
separating them from the mouth; frontal and parietal shields dis- 
2 4 
Fia. 21.—(1) Vipera berus ; (2) Vipera aspis ; (3, 4) Vipera ammodytes. 
(Natural size.) 
tinct, the former as long as broad, usually shorter than the space 
separating it from the rostral shield; 6—13 scales round the eyes ; 
one or rarely two series of scales between the eyes and the lips; 
nasal shield single, separated from the rostral by a naso-rostral 
shield ; temporal scales smooth. Body scaies in 21 rows (excep- 
tionally 19 or 23), strongly keeled; 132—150 ventral shields; 
38—36 subcaudals. 
Colour very variable, grey, yellowish, olive, brown, or red above, 
