50 .VERTEBRATES: MAMMALS. 



America. Beavers have a flat, scaly tail, and are wholly 

 aquatic in their habits, and their food is chiefly bark 

 and aquatic plants. Their teeth are very sharp and 



Fig. 91. American Beaver. 



powerful, enabling them to gnaw down trees of the 

 hardest wood. Beavers prefer running water, in order 

 that the wood which they cut may be carried to the 

 spot where it is to be used. They keep the water at a 

 given height by dams, which they build of trees and 

 branches mixed with stones and mud ; and they build 

 winter houses with the same materials. Each house 

 consists of two stories ; the upper story is above water 

 and dry, and serves as a shelter ; .the lower is beneath 

 the water, and contains their stores of bark and roots. 

 The only opening to the hut is beneath the surface of 

 the water. The color of the beaver is reddish-brown, 

 and the fur is soft and fine. It lives in the unsettled 

 parts of North America. 



The Pocket Gopher, Pouched Rat, or Geomys, of the 

 prairies of the Western States, is nine or ten inches 



