8 Proceedings of the Royal Physical Society. 



(b) Also that adult females vary in length from 19| 

 inches to 26 inches. 



That is to say, that males do not reach the maximum 

 length shown in females, the difference being generally from 

 one-half to one inch, I have previously shown this in the 

 measurements of another series (in "British Serpents"). 

 This series here confirms what I there stated, and it is of 

 importance, because G. A. Boulenger did not find the differ- 

 ence constant in a series he examined. The small red viper 

 is omitted in this estimate, as that reptile never grows to 

 more than 15 inches in either sex. 



(c) The upper labial scales in this series vary from 7 to 

 10 in number, the former figure occurring four times, the 

 latter twice. 



(d) The gastrosteges or ventral scales in the males in this 

 series vary from 132 in one case to 147, also in one case. 

 The former figure, 132, has never been recorded for males 

 before, so far as I am aware, the lowest being 137. 



(e) In the females of the series the gastrosteges vary from 

 140 in one case to 152, also in one case. 



(/) The urosteges, or sub-caudal shields, in the series vary 

 in males from 32 to 45, the lower and the higher figures 

 being both beyond the limits of the figures given in G. A. 

 Boulenger's article quoted. 



(g) In the females of the series, the urosteges vary from 

 28, the lowest recorded, to 38, the latter figure being 2 more 

 than mentioned as occurring. 



A British adder, therefore, may possess from 6 to 10 labial 

 scales (Boulenger records one with 6) ; from 17 to 23 rows 

 of scales across the body (Boulenger records one with 23) ; 

 from 132 to 154 ventral scales, the former figure recorded in 

 this series, the latter by Boulenger ; the sub-caudal shields 

 from 28 to 45, both here recorded ; the scales round the eye 

 vary between 6 and 11; the parietals may be represented 

 by the arrangement found in Vipera aspis instead of that in 

 Vipera ierus ; and other variations may be present which 

 this research does not deal with. 



I have undertaken this laborious counting simply to give 

 weight to my argument that it is an unsound and unscientific 



