128 RODENTIA. 



of pine, in others cleared lands and old pastures for its residence. 

 The Woodchuck is awkward and slow in its movements; its 

 safety is found in its extreme watchfulness and sharpness of 

 hearing. When at all alarmed, it flies to its deep and long bur- 

 rows, "thirty or forty of which have been seen in a field of five 

 acres." To these its dilated cheeks carry its winter stores. Its 

 fondness for clover often renders it an annoyance to the farmer. 



3d. GERBILLIDAE, or DIPODIDAE, JERBOAS. 



This family of the Rodents, sometimes called Jumping Mice, 

 are apparently formed to live on prairies and sandy deserts. 

 They have very short fore feet, and the hind ones very long, 

 being Kangaroos in miniature; the tail is generally longer than 

 the body, and used in leaping or walking; (Plate V. fig. 2.) the 

 forefeet are employed in conveying food to the mouth, and 

 seem of little or no use as organs of progression ; the fur is soft; 

 there are two cutting teeth in each jaw, the grinders simple or 

 compounded, six or eight beneath ; parts of the internal structure 

 are bird-like. As far back as the time of Herodotus, these Ro- 

 dents are alluded to as inhabiting Africa. 



Dipus, (Gr. 4i?, dis, two ; novg 1 pous, foot.) 



The animals of this genus have compound molars, and may be 

 regarded as an intermediate link between the Squirrel and the 

 Rat; but are more like the former than the latter. The fore legs 

 are very short, and scarcely used in walking ; the enormous hind 

 legs and tail at once remind the beholder of the Kangaroo. 

 When first seen, the animal seems supported in its rapid bounds 

 by only two long legs; whence the name Dipus, two-footed. At 

 a single bound, it moves four or five yards, and sometimes more ; 

 it feeds, sitting upon its haunches, like the Squirrel ; is found 

 abundantly in Egypt, Syria, and the north of Africa. The most 

 common species is D. sagitta, (Lat. arrow,) the Gerbo, or Egyp- 

 tian Jerboa, about the size of a large rat, living in large societies, 

 and constructing burrows under ground. 



Meriones. (Gr. [ITJQIOV, merion, a thigh.) The animals of this 

 genus are small, with long, slender, and nearly naked tails ; they 

 have six composite molars beneath ; their fore feet have a rudi- 

 mentary thumb, with a small nail. They hybernate, and are 

 nocturnal. 



M. Americanus, or Gerbillus Canadensis. The Deer Mouse ; 

 Jumping Mouse. This is about the size of a common mouse, 

 and of a reddish brown color ; has very short fore legs, long hind 

 ones, and a scaly, rat-like tail. It leaps ten or twelve feet at a 

 time ; is found in Canada and farther north, and as far south as 

 Pennsylvania, in fields of grass and grain. (PI. V. fig. 2.) 



