COUNTY AND DISTRICT DISTRIBUTION. 251 



Yorkshire it has the smallest average length of any- 

 where in England, while in some other parts of the 

 county it grows to 4 feet. 



The small red viper may be represented in some 

 of the small adders of this province, but the smooth 

 snake is unrecorded. 



XI. Tyne Province. 



Vipera herns. — This is a province where the adder 

 is by far the most common of our serpents, except in 

 one locality in the extreme south of Durham. In all 

 other parts the adder predominates, some observers 

 even considering it the only species indigenous to the 

 province. It has the large average length of 2 feet. 



Tropidonotus natrix. — The eastern slopes of the 

 Cheviots furnish what ring snakes are found in this 

 province ; at any rate the species is very rare in 

 other parts. 



The small red viper is found in both counties of 

 the province, but the smooth snake is, as usual in 

 the northern counties, unrecorded. 



XII. Lakes Province. 



Vipera berus. — According to the biological system 

 of county classification, which is adopted in these 

 records, the Isle of Man comes in the Lakes Prov- 

 ince. But the report furnished of snakes in the 

 island states one thing only — namely, that there are 

 no snakes there at all, so that from an ophidian 



