206 CASTOKIDJE. 



RODENTIA. CASTOR I DM. 



Fig. 77. 



a, c, Nat. size. Kent's Hole. 



ARVICOLA AGRESTIS. Field Vole. 



Young Water-rat, BUCKLAND, Reliquiae Diluvianse, p. 265, pi. 



xi. fig. 11. (?) 

 Petit Campagnol des Cavernes, CUVIER, Ossem. Fossils, v. pi. 1, p. 54. 



THE best preserved fossil specimens, from the caves at 

 Kirkdale and Torquay, of the jaws and teeth of the species 

 of Arvicola which are inferior in size to the common 

 Water-rat, appear to me to be identical with the corres- 

 ponding parts of two of our existing Voles. The jaw a, 

 and leg-bone c, figured above, agree with those of the 

 species with rootless molars figured by Mr. Bell in his 

 British Quadrupeds, p. 325, as the Field-vole, Arvicola 

 agrestis of Fleming, which is the Mus arvalis of Pallas. 



Cuvier cites the jaws, teeth, and a thigh-bone, appa- 

 rently of this little Rodent, from the cave at Kirkdale, 

 which parts, he says, do not surpass in size the common 

 Field- vole, {Mus arvalis, Linn.); but adds that the femur, 

 though of the same length, is sensibly thicker, (plus large 

 transversalemenf). The anchylosed tibia (f) and fibula (/), 

 fig. 77, from Kent's Hole agree, like the jaws, with that 

 of the existing Field- vole. A magnified view of the grind- 



