RODENT QUADRUPEDS. Fie | 
country at the time of the Revolution in the foreign 
ships. 
119. The Jerboas are singular animals, making an aber- 
rant genus of this family. They have long tails with 
oy tufted ends, and long 
: hind legs, which en- 
able them to make 
enormous leaps. The 
Egyptian Jerboa, 
Fig. 56, is about the 
size of a large rat. 
, 120. Of the Bea- 
| ver family, the com- 
mon Beaver, Fig. 57, 
so well known in Can- 
ada and the northern 
part of the United 
States, is the type 
species. It is distin- 
guished from all the 
other Rodents by its 
flat and scaly tail. 
Its hind feet are 
webbed, and with 
these and its tail it is 
expert In swimming. 
Its incisor teeth are 
large and uncom- 
Ne : monly hard, and with 
Fig. 57.—Beaver. them it can divide a 
common walking-stick at a bite with as clean a cut as 
that of a hatchet. Like the Seal (§ 101), it can close its 
ears and nostrils when it dives into the water. Beavers 
are very celebrated for the skill with which they build 
- their dams and habitations, which they always do in 
companies. ; 
121. The common Porcupine, Fig. 58 (p. 72), is found 
