596 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. [12] 



Sciurus chrysurus, Pucherau. 

 Panama to Colombia. 



Sciurus variabilis, GeoftYoy. Peruvian Squirrel. 



Panama to Bolivia. 

 Sciuropterus volucella hudsonius, (Gmelin) Allen. Northern Flying-Squirrel. 



Northern part of California and Pacific regions to the Rocky Mount- 

 ains and northward. 



Sciuropterus volucella volucella (Pallas), Allen. Southern Flying-Squirrel. 



United States except the northwestern portion. Mexico and Guate- 

 mala. 



Family HAPLODONTID^. The Sewellels. 



Haplodou rufus, (Eaf.) Cones. Sewellel. 



Pacific coast from l!forthern California northward. 



Family CASTOEID.E. The Beavers. 



Castor fiber, Linn^. Beaver. 

 North America generally ; Hudson's Bay to Mexico. 



Family MURID^. The Mice. 



Fiber zibethicus, (Linn^) Cuvier. Muskrat. 



North America. 

 Neofiber Alleni, True. Eound-tailed Muskrat. 



Southern Florida. (Georgiana.) 

 Cuniculus torquatus, (Pallas) Coues. White Lemming. 



Arctic America, Greenland, and corresponding latitudes of the old 

 World. 

 Myodes obensis, Brants. Lemming. 



Northwestern North America. Asia. 



'^ S3rnaptomys Cooperi, Baird. Cooper's Mouse. 



Indiana, Illinois, Kansas, Minnesota, Oregon, and Alaska. 



Evotomys rutilus, (Pallas) Coues. Red-backed Mouse. 

 Circumpolar regions. 



Evotomys rutilus Gapperi, (Vigors) Coues. Gapper's Mouse. 



Northern frontier of United States from ocean to ocean. Nova 

 Scotia, south to Massachusetts. 



. Arvicola pinetorum, (Le Conte) Baird. Pine Mouse. 



United States east of the Mississippi from Massachusetts southward. 

 Kansas, Oregon, and Mexico. 



Arvicola quasiater, Coues. 

 Mexico. 



