CHORDA I A 



387 



superficially do not greatly resemble the squirrels. One of 

 these is the beaver, Castor fiber {Fig. 377), the largest representa- 

 tive of this suborder; it is about sixty centimeters long, exclusive 

 of the tail, which is about twenty-five. The body is covered with 



FIG. 377. Castor fiber, the beaver. ( from a photograph piovided by the American Museum 



of Natural History.) 



soft fur, which is well known because of its commercial value ; 

 it is absent on the tail, which is broad, scaly, and flattened dor- 

 soventrally. The beaver is capable of felling large trees, of 

 damming streams, and of building houses for itself ; it feeds 



FIG. 378. 1, Sciurus carolinensis leucotis, the common gray squirrel, black variety; speci- 

 men from Pennsylvania. 2, Scinriis carolinensis extimus, the everglade gray squirrel; 

 specimen from Florida. 3, Sciurus carolinensis leucotis, the common gray squirrel of the 

 United States ; specimen from New York. (From a photograph provided by the American 

 Museum ot Natural History.) 



chiefly on the twigs of the trees which it fells. At one time it 

 was very generally distributed throughout the wooded regions 

 of the entire northern hemisphere, but it has been so extensively 

 hunted for its fur that it has been exterminated in many places. 



