RODENTIA-MURINAE-NEOTOMA CINEREA. 
499 
NEOTOMA CINEREA. 
Rocky Mountain Rat. 
Mus cinereus, Ord, Guthrie’s Geography, 2d Am. ed., II, 1815, 292.—(Based on the ash-colored rat of Rocky 
Mts. of Lewis & Clark.) 
Mijoxus drummondii, Rich., Zool. Jour. Ill, Apr. 1828, 517.—(R. Mts.) 
Wagner, Schreher Saugt. IY, tab. 227. A. 
Neotoma drummondii, Richardson, F. B. A. I, 1829, 137 ; pi. viii.—(Not of And. & Bach.) 
Prince Max. Reise. I, 1839, 365. 
Wagner, Suppl. Schreb. Ill, 1843, 560. 
Rat with hairy tail, Lewis & Clark, I, 1814, 289 ; II, 178. 
Sp. Ch. —Size of Norway rat. Fur very soft and smooth. Tail densely hairy, the vertebras shorter than the body 
without the head ; above narrowly lead gray, with the short basal wool light gray. Posterior third of soles furred. Above 
light yellowish brown, with some darker hairs intermixed, deeper on the sides. Under surface of body and tail, with feet, 
snowy white. 
A single specimen of this species was obtained by Dr. Suckley, on Milk river, Nebraska, on 
the 20th of August, 1853, where it was known as the prairie rat. It is not in sufficiently good 
order to supply a satisfactory description, but seems to agree perfectly with the account of 
Richardson, and differs in essential points from those specimens of Neotoma collected on the 
Pacific coast by Dr. Cooper. The fur is long, full, and very decidedly softer than that of N. 
occidentalis; the hairs are nearly of equal length, a few rather longer ones interspersed. The 
ears are very large and broad, scantily coated with short grayish hairs on both sides. The tail 
is shorter than the body, densely clothed with long hairs, with coarse wool interspersed. The 
posterior third of the soles is wooly. 
The prevailing tint of the upper parts is a clear, pale yellowish brown or light huff, clouded 
by the dusky tips of the longer interspersed hairs. Most of the hairs, however, are without 
dusky tips at all, being lead gray to near the yellowish tips. The outside of the legs is like the 
hack, hut the feet, with the whole lower parts, are white. The tail above is grayish lead color, 
the longer hairs being dark ash, the short wool intermixed, clear gray. Beneath, the tail is 
white, and this color is distinctly visible, viewed from above. The hair on the belly is pure 
white to the roots. 
Measurements. 
224. 
Inches. 
Lines. 
Nose to eve.. __ __ _ _ _ . __ ____ 
1 
9 
Nose to root of tail____ 
7 
Tail, from root to end of vertebrae __ _ __ 
5 
Tail, from root to end of hairs___........._ 
5 
10 
Ears, height posteriorly. _ 
11 
Ears, height internally above notch 
1 
Arm, fore foot to end of ('laws _ _ 
9 
Leg, hind foot from heel to end of claws..__,_...._ 
1 
5 
