SCIURlO/E— S0IUR0PTERU8 VOLUCKLLA. 



601 



cella, it having been previously referred by Linnseus to the Flying Squirrel 

 of Europe {Sciurus volans U\m\.z=.Scivropterm volans F. Cuv.). Richardson, 

 in 1828, described a variety of the Northern Flying Sq'iirrel, from the 

 northern portion of the Rocky Mountains, under the name Pteromys sabrinus 

 var. alpinus. Later, however, he was in doubt as to whether the differences 

 observed merited recognition. Wagner, however, in 1843, raised Richard- 

 son's variety alpinus to specific rank, since which time it has passed generally 

 current ns a species, being so recognized by Audubon and Bachman, and 

 Inter by Professor Baird. Bachman, in 1839, described specimens from near 

 tlie mouth of the Columbia River under the name Pteromys oregonensis, and 

 fliis name has since passed generally current as that of a valid species. The 

 differences supposed to characterize it were, however, slight, consisting, in 

 reality, only in its rather smaller size as compared with P. "sabrinua^'. From 

 /'. "volucel/a'^ it differed in being larger, and in not having the liairs of the 

 ventral surfacie white to the roots, as Dr. Bachman erroneously supposed to 

 be always the case in the Southern Flying Squirrel. This originated the 

 four supposed species of North American Flying Squirrels. Ten years later, 

 however, we find the following suggestive remarks in Audubon and Bach- 

 man's "Quadrupeds of North America" (vol i, p. 205), under the head of 

 P. "sabrinus'': — "As long as only two species of Flying Squirrels were 

 known in North America — the present species (P. sabrinus) and the little 

 /'. volu4xllti — there was no difficulty in deciding on the species but since 

 others have been discovered in the far West, the task of separating and defin- 

 ing them has become very perplexing." 



Professor Baird, in 1358, .laving few specimfitt: oi" the group at hand 

 for comparison, admittc ] r.r of the fo \r species, bu^ evidently with some 

 hv'sitation. P. '• volucella" seemed i.) him to be only a miniature of P. "hud- 

 sofi'uti", the only differences perceivable to him being the larger size of the 

 latter, with the hairs of the belly lead-colored at base instead of white 

 throughout. Respecting the distinctness of P. '^alpinus" from P. "hudsonius", 

 he felt unable to decide, while the validity of P. "oregonensii" was apparently 

 not questioned. . 



