108 RODENTIA. 



of opinion, that it does not become torpid, and that it is 

 solitary in its habits. In Europe it was found by him only 

 in desert places near the Volga and Astrachan, and on the 

 Caspian Sea ; it also inhabits Persia and Tartary. 



Genus DIPUS. 



Teeth.— Incisors, | ; molars, |^ or |^ =16 or 18 ; 

 lower incisors awl- shaped and very sharp ; grinders simple, 

 tuberculated ; head very wide ; eyes large ; ears long and 

 pointed ; fore-feet short, with four toes, the thumb re- 

 presented by a wart, surmounted by a nail ; hind-feet 

 five or six times as long as the fore-feet, with three or 

 five toes; tail very long, cyhndrical, covered with short 

 hairs, ending in a tuft of long hairs. Feeds on fruits and 

 roots ; burrows in the ground, becoming torpid in mnter : 

 the long hind-legs of these animals enable them to leap 

 with great power and swiftness. 



Dipus Gerboa. 



Dipus Gerhoa, Desm. Mamm, Sp. 509. 



Mus Jaculus, Linn. 



Dipus sagiiia, Pallas, Zoog. Eoss. As. 



The Jerboa. 



Desceiption. — Head very thick, and wide in proportion to 



the body ; ears generally shorter than the head ; hind-feet 



with three toes ; the two upper incisors vertical, grooved 



in the middle; eyes large, prominent, lateral, about an 



inch and a half apart. Eur long, very soft and silky on the 



upper parts of the body and on the sides ; the hairs are 



ashy for the greater portion of their length, then rufous, 



and at the tips blackish, whence results a general rufous 



tinge, varied -with, blackish ; the under parts of the body, 



the inside of the hind-legs, and a crescent-shaped mark on 



each side behind quite white ; fore -feet veiy short, white, 



