250 BRITISH SERPENTS. 



The small red viper occurs in Lincolnshire, and 

 probably in Leicestershire. Coronella austriaca is 

 unknown in the Trent Province. 



IX. Mersey Province. 



Vipera herus. — The adder is not common in this 

 area, which is not surprising when one considers 

 the immense population included in the province, 

 especially in tlie South and West Lancashire por- 

 tions. Even in Cheshire it is seldom met with, and 

 does not exceed an average of 18 inches. 



Trojndonotus natrix. — Delamere Forest in Clieshire 

 holds a good many ring snakes, the average length 

 being 3 feet. This species is by far the most common 

 in the Mersey Province. 



Neither the small red viper nor the smooth snake 

 occur, as far as known at present. 



X. Humber Province. 



Vipera berus. — The adder in Yorksliire exhibits 

 great variation, the size of the county being so great 

 as to allow of vastly ditferent local conditions in 

 various localities. Thus tlie size is found ranging 

 from 15 to 27 inches, two species being probably 

 involved. In the south and east of the province 

 the adder is probably more common than the harm- 

 less species. 



Tropidonotus natrix. — Great variation of size is 

 shown also in the ring snake here, and in North 



