ARVICOLA AMPIIIBIUS. 83 



Length of head and body, 2 feet 6 lines ; head, 5 inches ; 

 tail, 1 foot ; breadth of tail, 4 inches 2 lines ; some indivi- 

 duals attain the length of 3 feet. 



Lives solitary or in pairs ; burrows in the ground on the 

 banks of large rivers, differing in these respects from the 

 American Beaver. 



It is still found, though in greatly reduced numbers, in 

 several rivers of the northern and central countries of Eu- 

 rope, such as the Danube, Ehine, and Rhone, on which last 

 it is recorded (by Crespon) as occurring from Pont St. 

 Esprit to the sea, especially among willow plantations, on 

 which it sometimes inflicts serious injury. Is rather rare 

 in Russia, except on the Dwina and Petschora ; is nume- 

 rous in Siberia, Tartary, and the Caucasus (Pallas). 



Genus ARVICOLA. YOLES. 



Teeth.— Incisors, I ; molars, |^ = 16; molars deeply 

 sulcated outside, pressed so closely together that the divi- 

 sions between them are not easily seen. Muzzle blunt ; 

 toes separate ; tail round and liaiiy, shorter than the body ; 

 no cheek-pouches ; fore-feet with four claws, having nails, 

 and the thumb consisting of either a mere tubercle or a 

 very small nail ; hind-feet with five toes armed with nails, 

 the thumb very small ; eyes small or moderate. Burrows 

 in the groimd. 



Arvicola amphibius. 



Arvicola amphibms, Desm. Mamm. Sp. 435 ; Bell, Brit. Quad. ; De 



Selys, Micromm. 

 Lemmv.s aquaticus, F. Cuvier. 

 Water Vole, Water Rat. 



Description. — Tail blackish, lighter beneath, rather longer 

 than half the body, with upwards of 110 scaly rings ; ribs, 

 thirteen pairs. Fur dark brown, more or less rusty above. 



