420 U. S. P. R. R. EXP. AND SURVEYS—ZOOLOGY—GENERAL REPORT. 
PEROGNATHUS FASCIATUS, Pr. Max. 
Perognathus fasciatus, Pr. Max, Nova Acta C. L. C. Acad. XIX, 1, 1839, 369; tab. xxxiv.—Iz. Reise innere Nord- 
Amerika, I, 1839, 449. 
Waaner, Wiegmann’s Archiy, 1841, mu, 45.—Is. Suppl. Schreb. IM, 1843, 612. 
Leconts, Pr. A. N. Sc. Phil. 1853, 224. 
Avp. and Bacn. N. Am. Quad., IT, 1854, 341. 
Se. Cu.—Considerably larger than the house mouse. ‘Tail as long as the body without the head. Antitragus conspicu- 
ously lobed. Soles naked. Above reddish yellow, closely lined with black; fore legs all round, feet, and under parts 
white ; a pale reddish yellow immaculate band on each side. 
This animal is perhaps the largest of the genus, and if all the specimens referred to it are of 
the same species, has a very extensive range. The specimen before me (1061) is about the size 
of Tamias quadrivittatus, or about as long as the larger meadow mice, (Arvicola,) but more 
slender. The cheek pouch-openings are large, reaching further back than the lower jaw. The 
ears are larger than usual in Perognathus, projecting prominently ; the antitragus exhibits a 
conspicuous narrow elongated lobe. The concavity of the ear is thinly haired, the outside is 
more densely coated. 
The thumb is short but distinct, armed with a flat nail. The fore claws are a little longer 
than the hinder ones. The hind feet are moderately long; the soles naked along the central 
line from the heel. The tail is about as long as the body, exclusive of the head. It is thickly ~ 
eoated with rather long, stiff hairs, concealing the annuli; the terminal hairs but little longer ; 
the hairs on the upper surface of the terminal half, however, are rather longest, especially over 
the joints. 
The hair is everywhere stiff, harsh, and lustrous, not very close set, and much like fine spun 
glass ; there is no under fur whatever. 
The back and upper parts of the sides are of a light yellowish sandy, finely and uniformly 
lined with dark brown or black; the individual hairs are of the color of recently cut lead for 
the basal three-fifths, then pale reddish yellow, and narrowly tipped with black. The under 
parts and inside of the limbs, including the whole fore legs, the feet, and the sides of the 
muzzle, are white; on each side of the belly a broad distinct stripe of pale reddish yellow, 
commencing a little before the eye on the side of the upper jaw, and, passing across the shoulder, 
extends as far as the heel on the outer or anterior face of the hind leg, the exterior face of which 
is otherwise, colored like the back. The region immediately around the eye is reddish yellow ; 
separated in a measure from the yellow of the lower part of the cheeks by hairs largely tipped 
with black. There is no plumbeous at the bases of the hairs on the belly, or in the yellowish 
lateral stripe. The tail is white, with the exception of an indistinct dusky stripe on the face. 
Although the locality of this specimen is widely remote from that described by Prince 
Maximilian, (Chihuahua city, and the mouth of the Yellowstone,) I am unable to detect any 
differences in any respect. His is smaller, but the skull and teeth figured evidently belong 
to quite a young animal, as the tubercles of the molars are not yet ground off, which takes place 
in quite early life. 
No mention is made of the lobe of the antitragus, but this might readily be overlooked ; the 
naked soles are distinctly indicated in the diagnosis of the genus. 
A skin in the collection of the Philadelphia Academy, collected at Fort Riley, Kansas, by 
Dr. Hammond, agrees very well with this specimen, and with the description of Maximilian. 
