450 U. Ss. P. R. R. EXP. AND SURVEYS—ZOOLOGY—GENERAL REPORT. 
caruncle is discernible. The ears are large and broad, rather densely coated with longish hairs, 
which, in this case, as well as on the rest of the body, are longer than usual in Hesperomys. 
The base of the ear is concealed by the long hairs on the cheeks. The tail is nearly as long as 
the body, and the hairs on it sufficiently dense to obscure the muroid scaly rings. The fore 
foot is too much distorted to show the comparative length of the fingers. On the hind foot, the 
central three toes are longestand nearly equal. The fifth claw reaches to the base of the fourth. 
The sole is hairy to near the end of the metatarsus. 
The predominant color above is a mixed brown and pale yellowish gray ; beneath, dull 
whitish ; on the flanks and the outside of the ear, pale yellowish brown. Nowhere any tinge 
of rufous. The hairs above are lead color at their base, then dull grayish yellow, and tipped 
with dusky. On the sides, the yellowish is brighter and the dusky tips wanting, in great 
measure. The tail is dusky above, whitish beneath and on the sides, the difference of color 
scarcely discernible. The feet also are whitish. 
General dimensions. 
a 441, 
Inches. | Lines. 
if 
INOSERUGIOCCID Uti winetiaa = ae ee ee ie ete ete te earn 10 
TOO WO tall ae ae ote eee eo ete 2 2 
Tail, from root to end of hairs-.-------------- rs | Bae 
Bars; height postenorly oon == ae eae | 33 
internally, above notch_..---...-|-------- 4 
SVC U1 a a ee ee | rere 23 
Leg, hind foot, from heel to end of claws------|-------- 6 
SRE Wei See foc SeSetiee ci sceee seaebete| oases 94 
ongest hairs onthe back==-.02-—-=-ee—se—==-|o=eee=ae 3h 
This species appears to differ from the 22. humilis in longer tail, shorter hind feet, and the 
absence of any rufous on the body. The imperfect condition of the specimen prevents more 
minute details. The ears, however, are smaller, the auricle thicker, and covered with longer 
and coarser hairs than in Hesperomys, more as in Arvicola. The under parts are of a much 
purer white. 
List of specimens. 
Catalogue | Corresponding Locality. | Whence obtained. Original | Nature of | Collected by— 
number. | No. ef skull. | pumber.| specimen. | 
441 1306 Rocky Mountains, 39° | Capt. E. G. Beckwith, U.S.A. 13 Skins 2222 
| 
Mr. Kreutzfeldt. 
