314 PROCEEDINGS OF THE ACADEMY OF [1897. 



A REVISION OF THE WEST AMERICAN FLYING SQUIRRELS. 

 BY BAMUEL N. RHOADS. 



The recent acquisition of four fine specimens of an apparently 

 undescribed Flying Squirrel from the San Bernardino Mountains, 

 California, having made it necessary to go pretty fully into the 

 relationships and nomenclature of the described forms inhabiting the 

 Rocky Mountain and Coast Ranges of America, the author has 

 secured the loan of most of the available specimens of these in our 

 eastern museums and made them the basis of the following study. 

 Before passing to their consideration I would gratefully acknowl- 

 edge the loan, through Mr. F. W. True, of the study series of west- 

 ern Sciuropterus from the Smithsonian Institution, also the permis- 

 sion to examine specimens in the American Museum of Natural 

 History, and the loan of a valuable series of skins and skulls from 

 British Columbia from the collections of Messrs. E. A. and 0. 

 Bangs, through the courtesy of my friend, Mr. Outram Bangs. 



Besides these and a series of about forty specimens in my private 

 collection, I should specially refer to those in the collection of the 

 Academy of Natural Sciences of Philadelphia, including as they do 

 the type of Sciuropterus oregonensis (Bachman) and the supposed 

 type of Sciuropterus alpinus of Audubon and Bachman, collected by 

 J. K. Townsend. 



Previous to Dr. J. A. Allen's Monograph of the Sciuridce there 

 were, variously recognized, four species or varieties of American 

 Flying Squirrel : a, the small southern Sciuropterus volans (Lin- 

 na?us) (=S. volucella of authors) forming the type of its genus ; b, 

 the large S. sabrh\us (Shaw) (=$. hudsonius (Gmel.)) of the Hudson 

 Bay Regions ; c, the large S. alpinus (Richardson) of the eastern 

 slope of the Rocky Mountains ; and d, the smaller S. oregonensis 

 (Bachman) of the Pacific Coast lowlands near the mouth of the 

 Columbia River. 



In 1877 Dr. Allen 1 united these under one species " Sciuroj)terus 

 volucella," making the smaller southeastern animal the type and 

 recognizing " S. hudsonius " as a northern transcontinental subspe- 



1 Monog. N. Amer. Rod.. 1877, p. 655. 



