Xv HABITS OF RAIZOMYS 483 
species the large intestine is slightly shorter than the small 
intestine. In Rh. badius the two parts of the gut are almost 
exactly equal in length. There are three pairs of inguinal and 
two pairs of pectoral teats. The name Rhizomys appears to have 
been given to the animals of this genus for the reason that they 
feed largely on roots. They burrow, and, like many other 
burrowing animals, feed in the evening. As is the case with 
other forms, Rhizomys is said to burrow with the assistance of 
its teeth as well as of its claws. 
Fic. 237.—Bamboo Rat. Rhizomys badius. x 3. 
Tachyoryctes is an African genus closely allied to the last. There 
are three Ethiopian species. It is mainly to be distinguished by 
the different pattern upon the grinding surface of the molars. 
Fam. 5. Geomyidae—This family of burrowing Rodents is 
limited to North and Central America. The animals have cheek 
pouches, and small eyes and ears, in accordance with their mode 
of life. The claws of the fore-limbs are very strongly developed. 
The genus Geomys contains some eight species, which are 
Central and North American, not extending, however, far north. 
The incisors of the upper jaw are grooved with two grooves. 
There are three pairs of teats—one axillary, and the two remain- 
ing inguinal. 
Thomomys, without grooves on the incisors, reaches to Canada 
in the north, and does not extend as far south as the last genus. 
