﻿VIPERA 223 



from the frontal by one to three shields, very 

 rarely in contact with it. Six to ten scales round 

 the eye, usually eight or nine, the upper pre- 

 ocular usually in contact with the nasal ; a single 

 series of scales between the eye and the labials. 

 Nasal single. Temporal scales smooth. Upper 

 labials six to nine, usually seven or eight, usually 

 third or third and fourth below the eye. Three 

 (rarely four) lower labials in contact with the chin- 

 shields, of which there is but one pair. 



Scales in nineteen (rarely twenty or twenty-one) 

 rows, with two apical pits, strongly keeled on the back, 

 less strongly on the sides, outer row smooth. Ventral 

 shields 120 to 135 in males, 125 to 142 in females ; anal 

 entire; subcaudals 30 to 37 in males, 20 to 28 in 

 females. By adding the subcaudals to the ventrals in 

 a hundred specimens, the total numbers are 153 to 169 

 in males, 150 to 168 in females. 



Coloration. — Unlike its ally V. berus, V. itrsinii 

 shows no sexual differences in the coloration. The 

 ground colour of the back is usually yellowish or pale 

 brown, sharply defined from the darker grey or brown 

 colour of the sides ; some specimens, however, are of 

 an almost uniform brown ground colour. The light 

 colour of the back is relieved by a series of more or 

 less regular transversely oval, elliptic, or rhomboidal 

 dark brown, black-edged spots, some or all of which 

 may run together to form a wavy or zigzag band 

 (Plate XII.). Two or three longitudinal series of dark 



