Mammalia. 



263 



States is the beaver. It has webbed hind feet and a broad, 

 flat, scaly tail. All have read of its remarkable intelli- 

 gence and skill in felling trees and in constructing dams. 

 It was formerly widely distributed, but is now rare, owing 

 not merely to the fact that it has been trapped for its fur, 

 but also to the spread of civilization itself. 



Squirrels. The squirrels are a very interesting group, 

 not only on account of their active and graceful movements, 



FIG. 155. COMMON MOLE. 



but also on account of their human trait of laying up pro- 

 visions and their human mode of eating. Most attractive 

 are the tree squirrels, including the fox squirrel, the gray 

 squirrel, the red squirrel, and the flying squirrel. The 

 woodchuck, prairie dog, and gophers live in the ground. 

 The true gophers have large cheek pouches in which they 

 carry out the soil in digging their burrows. 



The Insect Eaters. This order is best represented by 

 our common mole, whose work of raising a ridge of sod is 



