102 
U. S. P. R. R. EXP. AND SURVEYS-47TH PARALLEL. 
probably by the Hudson Bay Company’s ships, and other merchant vessels. They are now exceed¬ 
ingly abundant in the storehouses of the Hudson Bay Company and the garrison. Before that, 
the hairy-tailed rat was alone found. The Indians (Nisqually) have given it the hairy-tailed 
rat’s name, Squawt hun, or large mouse.—(No. 9.) 
HESPEROMYS GAMBELII, Baird. 
Baird, Gen. Rep. Mammals, 1857, 464. 
Sp. Ch. —Tail a little less or about equal to head and body. Above, yellowish brown, much mixed with dusky, but without 
a distinct broad wash of darker on the back. Entire outside of fore leg, below the shoulders, white. 
Fort Dalles, Oregon Territory, 1855.—(42.) 
Dimensions. 
Inches. 
Lines. 
From point of nose to insertion of tail • •••••••••••••••.••••••••••••••••. 
3 
10 
Total length to tip of tail, (about) ........................................... 
7 
6 
Extreme stretch. •••. .... 
5 
2 
Length of ear, measured posteriorly. 
7 
Between ears,..... 
51 
5 
From heel to longest toe of hind foot 
9 
Whiskers. ..... 
1 
3 
Between eyes, measured from their convexities... 
6 
HESPEROMYS AUSTERUS, Baird. 
Oregon Mole. 
Baird, Gen. Rep. Mammals, 1857, 466. 
Sp. Ch. —Sooty brown, slightly mixed with yellowish brown on the cheeks and lower part of sides ; the dusky color extending 
to the wrist. Feet and under parts white. Tail well haired, as long as head and body ; lower half white. 
Many specimens of this species were obtained at Steilacoom.—(4, 5, 22, 86.) 
HESPEROMYS SONORIENSIS, Leconte. 
Hesperomys sonoriensis, Leconte, Pr. A. N. Sci. Phila. VI, October, 1853, 413. (Sonora.) 
Baird, Gen. Rep. Mammals, 1857, 474. 
Arvicola ( Hesperomys ) sonoriensis, Aud. & Bach. N. Am. Quad. Ill, 854, 296 (from Leconte.) 
? tins leucopus, Rich. ZooI. Jour. III. 1828.— Ib. F. B. Am. I, 1829 142. 
Sp. Ch. —Young, light ashy gray ; adult, with a tinge of yellow h brown ; neither is there any dorsal stripe. Tail 
scarcely longer than the body, exclusive of the head. Posterior tubercle of sole small, rounded, far forward. Soles hairy 
for half their length. Tail white, except a narrow line above of dusky. Ears large, with long hairs ; one-half of the ear 
hoary, in strong contrast with the dusky of the remaining portion. 
Specimen obtained at St. Mary’s Mission, Rocky mountains. 
NEOTOMA OCCIDENTALIS, Cooper. 
Bushy-tailed Rat* 
Baird, Gen. Rep. Mammals, 1857, 496. 
Sp. Ch.— Size of Norway rat. Fur harsh. Tail densely hairy; the vertebrae as long or longer than the body, without the 
head. Color above, brownish plumbeous, mixed with yellowish brown. Beneath, with feet, bluish white. 
New Dungeness, Straits of de Fuca.—(149.) 
