68 



VERTEBRATES : MAMMALS. 





American Beaver, C. canadensis, Kuhl. 



6l - in the banks, 



whitherthey 

 retire when 

 their houses 

 are attacked. 

 The general 

 color of the 

 beaver is a 

 uniform red- 

 dish-brown, 

 and the fur 

 is of the best 

 quality, and 

 was former- 

 ly very valuable. Only two species are known. 



The American Beaver, C. canadensis, KuhL, found all 

 over North America ; and the European Beaver, C. fiber, 

 Linn., of the Old World. . These are much alike. 



The Genus Castoroides comprises the Fossil Beaver, C. 

 ohioensis, Foster, of New York and westward, known only 

 from its skull, which shows that this beaver-like Rodent 

 was six times the bulk of our living species. 



The Genus Myopotamus comprises the Couia, M. coi- 

 pus, Cuv., of South America, which resembles the beaver 

 in size and habits, but has the tail round and long. The 

 fur is yellowish-gray, and is known among the hatters 

 under the name of nutria. 



The Genus Aplodontia comprises the Sewellel, A. lepo- 

 rina, Rich., of Puget's Sound, which is about the size and 

 general appearance of the muskrat, but with the tail very 

 short and much depressed. 



SACCOMYID^E, OR POUCHED GOPHER FAMILY. This 

 Family comprises Rodents which have large and distinct 

 external cheek-pouches, pelage composed of stiff hairs 

 with no under fur, molars ^J, and the upper lip not cleft. 



