NEW AMERICAN QUADRUPEDS. 101 
industry and zeal of our travellers and naturalists, 
Drummond, Douglass, and Townsend, (the two 
former having perished in their ardor to advance 
the cause of natural science,) have greatly added 
to our list of the species of this genus, yet much 
remains to be done, and a wide field is still open 
for farther discoveries. The far west seems to he 
a region where the genera Lepus, Arctomys, and 
Spermophilus, principally abound, and rich stores, 
in every department of Natural History, lie in 
wait, to reward the zeal and enterprise of future 
naturalists. 
The following Species must be added to the List of 
Mr. Townsend's Quadrupeds. 
Pteromys oregonensis. Oregon Flying Squirrel. 
Characters . — Intermediate in size between P. 
volucella, and the northern Pteromys sabrinus. 
Ears longer than in the latter species; fur more 
compact ; the lobe of the flying membrane joining 
the fore foot, much longer in proportion, making 
that membrane broader ; foot larger ; general color 
above brown, beneath yellowish-white. 
Description . — All the fur of this species is deep 
gray at the base, that of the back tipt with yellow- 
ish-brown; tail pale brown above, dusky towards 
the extremity ; beneath brownish-white. Whiskers 
numerous, and very long, chiefly of a black color, 
and grayish at the tips. Hairs covering the flying 
