VARIATIONS OF THE VIPER IN GREAT BRITAIN. 9l 



As a rule, a single row of scales intervenes between the eye 

 and the upper labials, but one specimen (from the Isle of Arran) 

 has two rows on one side, as in V. aspis, and others have two 

 series except just below the centre of the eye. I have also 

 French and Norwegian specimens with two series of scales, either 

 complete or interrupted by a single scale between the eye and 

 the fourth labial. I would recommend special attention to this 

 point, and the preservation of any specimen showing two series 

 of scales between the eye and the labials. 



/. Finally, the scales between the prseoculars and the nasal 

 are not unfrequently totally absent. 



5. The Scaling of the Body. — The scales number 21 

 across the middle of the body. But there are exceptions. In 

 one specimen from Petersfield I counted 23 scales, and in another 

 from Scotland only 19. Two specimens from Norway with 19 

 scales are also preserved in the British Museum. Such excep- 

 tional specimens should be recorded and preserved. 



6. The Ventral Shields. — In 37 British specimens I have 

 counted 137 to 146 ventral shields (exclusive of the anal) in 

 males, J 39 to 154 in females. In foreign specimens 139 to 147 

 in males, 135 to 153 in females. The limit of variation on record 

 (sexes not discriminated) is from 124 to 159.* 



7. The Subcaudal Shields. — These shields are usually in 

 pairs, but it may happen that some are single. The number 

 (counting each pair as one, and not reckoning the terminal, 

 conical, or spine-like shield) is 35 to 40 in males, 28 to 35 in 

 females, in British as well as in foreign specimens. In one male 

 specimen from Petersfield I find as few as 33 shields, most of 

 which are single. The number of subeaudals is stnted, on reliable 

 authority, to vary between 25 ( 2 ) and 48 (<?). 



8. The Coloration varies greatly, and, with the possible 

 exception of totally black individuals, apparently irrespective of 

 localities. Whitish or pale grey specimens, with black belly and 

 jet-black dorsal zigzag band and spots, are males. Brown and 

 brick-red specimens, with the markings of a more or less dark 



* I have my doubts respecting a female specimen from Casaleone, 

 Verona, recorded by Camerano (I. c. pp. 24, 25) as with 168 ventral s and 

 42 caudals. I suspect it to be a V. aspis, in which species the number of 

 ventrals varies between 136 and 158 in the specimens before me, and the 

 tramber of subcaudals between 32 and 38 ( $ ) and 37 and 48 (<?). The 

 number of 178 ventrals given by Newman (Zool. 1869, p. 1660) is no doubt 

 due to some error. 



