RODENTIA. 95 



becoming- sooner worn, so as to form transverse elevations. Their superior 

 incisors are furrowed with a groove; their hind feet are somewhat longer in 

 proportion than those of Rats in general, and their thumb and little toe 

 slightly separated. Their tail is long and hairy. The sandy and warm parts 

 of the eastern continent produce several species. 



G. indicus. (The India Gerbil.) Size of the fat Dormouse; fawn-co- 

 loured above, whitish beneath; tail longer than the body, and blackish at 

 the end. The 



MERIOITES, Fred. Cuv. 



Which we separate from the other Gerbils, have the hind feet still lon- 

 ger; the tail nearly naked, and a very small tooth before the superior mo- 

 lars; characters which approximate them to the Jerboas. Their upper 

 incisors are grooved like those of the Gerbils, and their toes also are similar. 

 There is a small species in North America, the 



Mus. canadensis, Penn. (The Jumping Mouse.) Sizeof a Mouse; fawn- 

 coloured grey; tail longer than the body. A very active animal, that shuts 

 itself up in its burrow, and passes the winter in a state of lethargy. 



CBICETUS, Cuv. 



The Hamsters have nearly the same kind of teeth as Rats, but their tail 

 is short and hairy, and the two sides of their mouth are hollowed into sacs 

 or cheek pouches, in which they transport the grain they collect to their 

 subterraneous abodes. 



C. vulgaris. (The Common Hamster.) Larger than the Rat; of a red- 

 dish-grey above, black on the flanks and underneath, with three whitish 

 spots on each side. The feet, a spot under the throat, and another under 

 the breast white; some individuals are all black. This animal, so agreeably 

 varied in colour, is one of the most noxious that exist, gathering large 

 quantities of grain with which it fills its burrow that is sometimes seven feet 

 deep. It is common in all the sandy regions, that extend from the north 

 of Germany to Siberia. 



This last country produces several small species of Hamsters described by 

 Pallas. 



ABVICOLA, Lacep. 



The Arvicolac, like the Rats, have three grinders every where, but with- 

 out roots, each one being formed of triangular prisms, placed on two alter- 

 nate lines. They may be subdivided into several groups, viz. 



FIB EH, Cuv. 



The Ondatras or Musk Rats having semi-palmated hind feet, a long scaly 

 and compressed tail, of which one species only is well known: 



F. vulgaris. (The Canadian Musk-Rat or Ondatra.) As large as a Rab- 

 bit, of a reddish-grey. In winter they construct, on the ice, a hut of earth, 



