MOUSE TRIBE— POCKET-GOPHERS— KANGAROO-RATS 337 



{Peromyscus americanus), which in some cases inhabits open fields, although it 

 apparently prefers forest, and does not, like the European hamster, hibernate. On 

 the contrary, it is often seen running about in the snow, on which its long tail 

 leaves a characteristic track. In the north of its habitat it nests in cavities of 

 trees, fallen trunks, or holes in the ground, while in the south it hangs its nest of 

 moss, grass, and leaves on a horizontal twig, this nest being always provided with an 

 entrance-hole below. Not only the natural gracefulness and vivacity of its move- 

 ments, but also its fine colouring make this mouse one of the most beautiful of the 

 smaller inhabitants of the North American forests. When very young this species 

 is of a dull grey, but later on it becomes of a bright fawn-colour, its snow-white 

 feet and under-parts being in strong contrast to the rest of its body. With its 

 pearl-like eyes, large ears, and long tail, this mouse in general appearance is not unlike 

 the European house-mouse, which it also resembles in size. To mention in detail 

 any other members of the group would be impossible in our space, but it may be 

 observed that the species of the genus Rhithrodontomys take their name from their 

 grooved front-teeth. An allied sub-group is represented by the Florida wood-rat 

 (Neotoma floridana), an agile climber found both in forests and on rocky ground, 

 which produces from three to six young twice a year. These, like certain young 

 opossums, cling to the sides and back of their mother, even when she is walking. 

 This species has a thin scaly tail, but the bushy-tailed wood-rat (N. cinerea), which 

 is confined to the north-western and western States, has a tail more like that of a 

 dormouse. Wood-rats have grooved upper incisors. The true voles are represented 

 in the United States by species belonging to the European genera Microtus and 

 Evotomys, as well as by others assigned to peculiar genera under the names of 

 Phenacomys and Synaptomys. The musquash (Fiber) has been already mentioned 

 in the chapter on the Canadian fauna, as have likewise the lemmings of the genera 

 Lemmus and Dicrostonyx. 



Of the exclusively American family Geomyidce, to which allusion 

 Pocket-Gophers. \ f J 3 



has also been made in the chapter just referred to, the common 



pocket-gopher (Geomys bur sarins), which inhabits the basin of the Mississippi, 

 whence it ranges as far north as the Canadian border, is about 8 inches long 

 and has a soft mole-like coat of a reddish brown colour above, and greyish 

 beneath, the feet and generally the tail being white. In habits it resembles a 

 mole, but feeds on roots, nuts, seeds, etc., and in cultivated districts on potatoes, 

 which it is said to carry away to its provision-stores in its pouches. The provision- 

 chamber is connected by a passage with the living habitation, which is generally 

 situated beneath the roots of a large tree, about 5 feet below the ground, and 

 lined with grass. When this chamber is inhabited by a female, it is generally 

 connected with a circular, horizontal passage resembling that of a mole's burrow, 

 which probably serves as a refuge. 



The kangaroo-rats agree with the pocket-gophers in the posses- 

 Kangaroo-Rats. . & ° . . , 



sion of external cheek-pouches, as well as by their internal structure, 



but are distinguished by their long hind-legs, long tail, large eyes, and well- 

 developed external ears, as well, moreover, as by their habits. They represent 

 in America the jerboas of Asia and Africa and the jerboa-rats of Australia, 

 inhabiting the very driest regions, where they live in holes dug by themselves 

 vol. 11. — 22 



