122 SCIUROPTERUS. 



Sciuropterus volans alpinus Elliot, Syn. N. Am. Mamm., F. C. M. 

 Pub., II, 1901, p. 109. Zool. Ser. 

 Richardson's Flying Squirrel. 



Type locality. Head waters of the Athabasca and Peace Rivers, 

 Alberta, Canada. 



Geogr. Distr. From the Mackenzie River along east side of the 

 Rocky Mountains to the United States border. 



a. Sciiu'opteriis (ilpiiiiiH zdfilid'uH Osgood. 



Sciuropterus alpinus zaphceus Osgood, Proc. Biol. Soc. Wash., 

 xviii, 1905, p. 133. 

 Dusky Alaskan Flying Squirrel. 



Type locality. Helm Bay, Cleveland Peninsula, Alaska. 



Geogr. Distr. Only known from the type locality. 



Genl. Char. Similar to 5. alpinits, but darker. 



Color. Above pale russet; dusky line from base of whiskers to 

 and around eye, thence gray to posterior base of ear; lateral line 

 black; upper side of forearm blackish brown; sides of throat grayish; 

 axillary region creamy buff; throat whitish; breast and middle of 

 belly creamy buff; sides of belly and under side of hind legs pale 

 creamy mixed with dusky ; anal region pale russet mixed with dusky ; 

 hairs of tail above subterminally broccoli brown, overlaid with black; 

 beneath more rufescent, with an indistinct grayish median line; 

 upper side of fore and hind feet blackish brown. 



Measurements. "Total length, 311; tail vertebrae, 133; hind foot, 

 42. Skull: basilar length of Hensel, 32.3; occipito-nasal length, 41.4; 

 zygomatic breadth, 26.2 ; constriction in front of postorbital processes, 

 8.3; median length of nasals, 12.8; upper tooth row, 8.2." 



b. Sciuropterus alpinus calif ornieus Rhoads. 



Sciuropterus alpinus californicns Rhoads, Proc. Acad. Nat. Scien. 



Phil., 1897, p. 323. 

 Sciuropterus volans californicns Elliot, Syn. N. Am. Mamm., 



F. C. M. Pub., II, 1901, p. no. Zool. Ser. 

 Californian Flying Squirrel. 



Type locality. San Bernardino Mountains, southern California. 

 Geogr. Distr. Mountain ranges, southeastern California. 



c. Sciu/'opfcrus (t I pi II IIS orcgoncnsis (Bachman). 



Pteromys oregonensis Bachm., Jour. Acad.. Nat. Scien. Phil., 1S39, 



p. lOI. 

 Sciuropterus volans oregonensis Elliot, Syn. N. Am. Mamm., 



F. C. M. Pub., II, iqoi, p. no. Zool. Ser. 



