VIPERA 235 



or pale orange below, rarely coral red, more com- 

 monly in females than in males. 



The iris is usually coppery red, more rarely golden 

 suffused with brown. 



Black specimens occur, more or less frequently, all 

 over the habitat of this species, and are often referred 

 to as V. prester, Linnaeus. A distinction has to be 

 made between individuals which are black through 

 darkening of the ground colour, and such as are thus 

 coloured through expansion and confluence of the 

 markings. The latter are males, and among them 

 we may find intermediate stages showing how this 

 melanism is brought about ; in one case the black of 

 the back is separated from the black of the sides by 

 a narrow light brown wavy stripe, the remains of 

 the ground colour. When, as in all females, and 

 occasionally in males, the black is the result of a 

 gradual darkening of the ground colour, the typical 

 markings may still be detected under certain lights. 

 Some specimens (from Schneeberg, Lower Austria) 

 are black, with scattered golden dots, or of a dark 

 mahogany brown speckled with yellowish. In 

 nearly all the black specimens at least a few dots of 

 whitish are visible on the lips, and of yellow under 

 the end of the tail. 



Most of the variations enumerated above occur irre- 

 spective of the geographical distribution. Two forms, 

 however, deserve to be regarded as ill-defined local 

 races : the var. seoanei, Lataste, from North-Western 



