1897.] NATURAL SCIENCES OF PHILADELPHIA. 315 



cies or " variety " of volucella, with alpinus and oregonensis as its 

 synonyms. Until 1896, Dr. Allen's ruling, at least in reference to 

 the inseparability of the northern and southern forms of our eastern 

 Flying Squirrels as distinct species, was generally accepted. 



In that year Mr. Outram Bangs, having made a study of a much 

 better series of specimens than was accessible to Dr. Allen, showed 2 

 that the habitats of sabrinus and volans overlapped, the two forms 

 not intergrading over this common territory. So far as my study 

 of the western forms has made it necessary to consult the eastern 

 species, the verdict of Mr. Bangs appears fully sustained, and the 

 cranial and external characters of the Sciurop>teri inhabiting our 

 country from the Rocky Mountains westward to the Pacific seem to 

 equally justify their specific separation from any of our eastern 

 species. 



The first name specifically given by a naturalist to a western Fly- 

 ing Squirrel was imposed by Richardson in the London Zoological 

 Journal of 1828, pages 519, 520. In this place he describes a 

 squirrel taken on the second Franklin Expedition of 1825-26 as 

 follows : — 



" 12. Pteromys alpinus [here follows Latin description of charac- 

 ters], Rocky Mountain Flying Squirrel; yellowish-brown above; 

 tail flat, longer than the body, blackish-gray, flying membrane with 

 a straight border. Size greater than that of the Siberian Flying 

 Squirrel. Hab[itat]. — The valleys of the Rocky Mountains." 



In 1829 3 he more fully described the animal, comparing it with 

 Sduropterus sabrinus and reducing it to a variety of that species. 

 From this article we are enabled to fix definitely the type locality 

 of alpinus to be the headwaters of the " Elk" [—Athabasca] and 

 " South Branch of the Mackenzie " [=Peace] Rivers, on the east- 

 ern drainage of the main range of the Rocky Mountains in north- 

 western Alberta and east central British Columbia. From Rich- 

 ardson's account of the itinerary and labors of Drummond, who 

 collected the type specimens, the one first mentioned was probably 

 taken by Drummond when he returned after his fifty mile exploration 

 of the Columbia Portage Road " to the head of Elk River, on which 

 he passed the winter [1825-'26] making collections." 4 



It has been found impossible to secure any good specimens of 



2 Proc. Biol. Soc. Wash., 1896, pp. 162-167. 



3 Faun. Bor. Amer., 1829, pp. 195, 196. 



4 Ibid, Introd., pp. xvi, xvii. 



