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 LIPUS. 



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, cylindrical, covered with short 

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

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

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

 with great power and swiftness. 



Dipus Gerboa. 



Dipus Gerboa, Desm. Mamm. Sp. 509. 

 Mus jaculus, Linn. 



Dipus sagitta, Pallas, Zoog. Boss. 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. Pur 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 very short, white, 



