COMMON FIELD-VOLE. 



323 



RODENT I A . 



COMMON FIELD- VOLE. 



Arvicola agrestis. (Linn.) 



Specific Character. Greyish*brown, beneath pale grey, feet dusky. Tail 

 only one-third the length of the body. The second upper grinder has five 

 spaces and six angles ; the third six spaces and eight angles ; the first lower 

 grinder nine spaces and eleven angles. 



Mus agrestis, LINNAEUS, Faun. Suec., II. 11, No. 30. 



,, gregarius, ,, Syst. Nat. L, 84, No. 16. 



Arvicola ayrestis, DE SELYS, Bui. Acad. Brux., 1840. 



THIS species was first described by Linnaeus, but was 

 afterwards generally confounded with the common Vole 

 of the continent, and thus A. agrestis and A. arvalis are 

 constantly given as synonymous, although the animals are 

 very distinct in nature. A. agrestis may always be dis- 

 tinguished by the character of its second upper molar, 

 which has five cemental spaces, whereas the same tooth in 

 A. arvalis, as in all the other European Voles, has only four 

 spaces. It seems not a little strange that the last-named 



