254 viperim; 



A more or less distinct dark blotch on the lower lip, 

 involving five or six labial shields without interrup- 

 tion. Lower surface of end of tail yellow. 



Size. — This Viper exceptionally attains a length 

 of 3 feet. The largest male in the British Museum 

 measures 2 feet 6 inches, the largest female 2 feet 

 4 inches. In V. berus females grow to a larger size 

 than males ; in this species, as in V. aspis, the reverse 

 appears to be the rule. 



Hybrid. — A female specimen, presumed to be a 

 hybrid between V. berus and V. ammodytes, was 

 obtained by Captain Veith in 1902 in Carinthia, in 

 a locality where both these species occur together. 

 The shape of the head is exactly that of a typical 

 V. aspis, the snout distinctly turned up at the end, 

 but without wart or scaly appendage, the raised 

 portion being covered by the apex of the rostral 

 shield and three apical shields. The rostral shield, 

 which is a little deeper than broad (5 : 4), ex- 

 tends above the level of the slightly raised canthus 

 rostralis, which bears two shields, the second in 

 contact with the supraocular. The naso-rostral 

 extends to the canthus rostralis, where it joins the 

 first canthal and the lateral apical shield ; one series 

 of scales between the nasal shield and the preoculars. 

 On the upper surface of the head the snout is 

 covered with fifteen subimbricate smooth scales, 

 in addition to the canthals and apicals. A frontal 

 shield and a pair of parietals are well developed, 



