92 W. T. Blanford— On the Voles (Arvicola) of the [No. 2, 



upper molar with 4 spaces, 3 outer and 2 inner angles. Interparietal 

 bone with the hinder edge raised in the middle, concave towards the 

 sides, with a projecting point in the middle in front, obliquely trun- 

 cated on the sides, and terminating in long points projecting outwards 

 and backwards. Dorsal surface of body grey of various shades to 

 brownish black. 

 This comprises A. amphibius, A. nivalis, A. ratticeps, and A. hrandti. 



C. Agricola. 



First lower molar with 9 spaces, 5 outer and 6 inner angles ; second upper 

 molar with 5 spaces, and 3 angles both inside and outside ; second 

 lower molar with 5 spaces and 3 angles on each side. The inter- 

 parietal elevated into a flat convexity along the whole width of the 

 hinder margin, produced into an angle in front, and cut off almost at 

 a right angle at the sides. The dorsal surface of the body dark 

 blackish, brownish grey. 

 The only European form is A. agrestis. 



D. Arvicola. 



First lower molar with 9 spaces, 5 outer and 6 inner angles ; second upper 

 molar with 4 spaces, 3 outer and 2 inner angles ; socond lower molar 

 with 5 simple spaces and 3 angles, both outside and inside. Inter- 

 parietal convexly swollen throughout the whole breadth of the hinder 

 margin, produced in front into a middle point, attenuate at the sides 

 and sharply truncate, with a short oblique pointed projection directed 

 outwards and backwards. Dorsal surface grey of various shades* 

 This, the typical form, is again divided into : — the Long-eared Voles, 

 Arvicola — with 8 mammse (4 on the breast, 4 on the groin), the planta 

 with 6 distinctly separate roundish tubercles, the ear projecting beyond 

 the fur, and the eye rather large ; and the Short-eared Voles, Microtias — 

 with only 4 mammse, all on the groin, the planta with 4 tubercles, ears 

 concealed by the fur, and eye very small. The first comprises the European 

 A. campestris and A. arvalis and several Asiatic species, such as A. socialis, 

 A. saxatilis, and A. gregalis ; the second A. subterraneus and A. savii. 



The American species have been similarly classified by Baird* and 

 Couesf. The only European section said to be represented in America is 

 the Hypudceus of Keyserling and BlasiusJ, for which, as it is not the 

 original Hypudceus of Illiger§, Coues has proposed the name Evotomys. 

 It appears probable that this name must be adopted for the section of 



* Mammals of North America, pp. 509-553 (1857). 



f Monograph of North-American Rodentia, pp. 152 &c. (1877). 



X Wirbeltliiero Europa's, p. 34. 



§ Prod. Syst. Mam. Av. p. 87. 



