464 



MESSRS. BLACKMORE AND ALSTON 



[June 16, 



Runton are much smaller, being slightly less (and the jaws perhaps 

 more slender) than in a Swiss skull of the small terrestris race. It 



Fig. 1. 



Teeth of A. amphibius. 



is evident, therefore, that Prof. Owen was right in refraining 

 from definitely separating these fossils from the recent A. amphibius, 

 although the animal may of course have been sufficiently distinct, 

 and also that the deposits in which they occur are much more recent 

 than was formerly supposed. 



At the present day A. amphibius ranges throughout all Europe, 

 and extends through the Caucasus to Persia, and to Northern Asia 

 as far as the Sea of Okhotsk. The destructor race inhabits the 

 Mediterranean countries ; and the small terrestris form is principally 

 found in the mountainous parts of Central Europe. Remains of the 

 Water-Vole are found abundantly in many drift-deposits, and in 

 most of the bone-caves of England, France, Belgium, and Germany. 



The form of the teeth is very constant, except in minor details, 

 and does not vary in the different races. The pattern is : — 



Upper I. 5 spaces, 6 angles. Lower I. 7 spaces, 9 angles. 

 II. 4 „ 5 „ „ II. 5 „ 6 „ 



„ III. 5 „ 6 „ „ III. 5 „ 6 „ 



"We have compared the fossils in the British, Norwich, and 

 Taunton Museums, and in our own collection with recent skulls 

 from England, Scotland, and Switzerland. 



3. Arvicola ratticeps, Keys, et Bias. (?). 



1870. Arvicola ratticeps, Sanford, Q. J. Geol. Soc. xxvi. p. 125, 

 pi. viii. fig. 1 a-d. 



Among the Somersetshire cave-fossils in the Taunton Museum, 

 Mr. Sanford recognized a part of a skull and several lower jaws as 

 being undistinguishable from this northern species. In 1861 we 

 had found a large number of jaws and other remains in a deposit of 



