ORDER RODENTIA. 109 



altogether disused. In winter, when they are less offensive, 

 the flesh is said to be good food.. 



The subgenus Arvicola, or the Campagnols, was con- 

 founded with the Linnean genus Mus, until Lacepede sepa- 

 rated it under the name Arvicola, and Cuvier under that of 

 Lemming. Illiger adopted Hypudseus and Georychus as 

 the generic names of this subdivision. 



Of the various divisions created by modern systematic 

 writers of the Linnean genus Mus, it may well be ques- 

 tioned how far they are really useful in the propagation of 

 zoological knowledge. As a subdivision, which the Tyro 

 in zoology may pass with venial indifference, though the 

 professor of the science may employ it with advantage, 

 it may be, in common-place language, all very well. 

 Close and careful comparison may detect some difference 

 in the minutiae of the conformation of the teeth of Arvicola, 

 and in those of the Ondatra and Lemmings, properly 

 speaking ; but the principal difference after all will be found 

 to appertain to the tail, which in the Ondatra is scaly 

 without hair, but in the Arvicola is covered with scales in 

 conjunction with hair. 



In addition to the Baron's specific notice, we shall only 

 add, that the Water-Rat varies by climate. Its head is 

 large ; the muzzle short and thick ; the eyes small ; and 

 the ears short, and hidden in the fur ; the tail is scaly, like 

 that of the Rat, but more furnished with hair ; and there 

 are small scales on the skin of the feet ; the fur is long ; the 

 incisive teeth are yellow. The feet are not palmated, 

 though the habits of the animal are aquatic. There are 

 five toes on each foot, but the thumb of the anterior extre- 

 mities is extremely short. 



The denomination of Water-Rat sufficiently indicates the 

 habits of the animal. It is never found like the common 

 Rat in our habitations, nor does it frequent elevated or dry 



Vol. HI. K 



