ANIMALS. 339 



two great bunches on each side of the jaw, it returns home to its 

 hole to deposit the spoil as a store for the winter. The size, the 

 fecundity, and the voraciousness of this animal, render it one of 

 the greatest pests in the countries where it is found, and every 

 method is made use of to destroy it. * 



• Among animals of tliis kind, wliich are furnished with pouclies on eacli 

 side the mouth, the most remarkable is the Canada rat. Its size is that of 

 the Norway rat, though of a more leng-thened form. Its colour is a pale 

 grayish-brown, paler beneath. Tlie pouches attached to the cheeks are of a 

 very large size, shaped somewhat like an egg, reach to the ground, and have 

 the appearance of a pair of inflated bladders. 



The Atiomalous Hamster, found in tlie Isle of Trinity, is about the size of 

 the common rat, bxit the nose is more pointed ; the ears are naked, round, 

 and of moderate size : the pouches are formed by a duplicatiu-e of the common 

 tegument, like the pouch of the opossiun, and are of considerable size. The 

 body is covered with fine lauce-shaped spines, stronger ou the back than 

 elsewhere, intermixed with hair. This species differs perhaps generically 

 from the other Hamsters, with which, indeed, it seems to have no otlier 

 relationship than by the cheek-pouches. 



The genius Gerboa approximates considerably to the rats properly so 

 called, by a great number of characters of internal organization, but is suf- 

 ficiently distinguished by the shortness of the anterior limbs, and the length 

 of the hinder extremities, or to speak more correctly, of the liinder meta- 

 tarsi, and by the tail, which is covered ivith long hairs at its extremities. 



As to external conformation, the Gerboas exliibit some relations with the 

 kanguroos. The form of the body is the same in general The hinder 

 limbs are likewise five or six times stronger than the fore. In both genera 

 the tail is very long ; the ears elongated, and pointed, and the eyes very 

 large and round. But though the Kanguroos have so many treats of exter- 

 nal conformation similar to the Gerboas, they are infinitely removed from 

 them in most important points^ such as the organs of generation, ventral 

 pouch, &c. 



Tlie Gerboas have the same teeth as the rats, that is, they have two in- 

 cisors in each jaw; and the lower, instead of being flat and cut scissors- 

 like, as the upper, on the contrary, are conic and pointed. The molars are 

 generally six in niunber, three on each side. They are slightly sloped. 

 There is sometimes an additional one in the upper jaw. In the Gerboas the 

 cheek-bones are very prominent, which gives a singular and flatted form to 

 the front part of the head. The muzzle is short, large, and obtuse. A con- 

 siderable number of stiff hairs extend on each side, and form long musta- 

 phios. The nose is naked, cartilaginous, and in one species rather compli- 

 cated. The ears are long and pointed ; the eyes large, and placed altogether 

 on the sides of the head. 



The body is a little elongated, larger behind than before, and well covered 

 with soft and silken hairs. The fore-feet are ver>' short and feeble. They 

 have four or five toes according to the species. The thvunb or interior toe, 

 where it exists, is very short, rounded at its extremity, and provided with 

 an obtuse nail. The otiier toes are long and anned with crooked nails. The 

 hind-feet are a.s disproportioncd as those of the kanguroos, being four or 



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