420 U. S. P. R. R. EXP. AND SURVEYS ZOOLOGY GENERAL REPORT. 



PEROGNATHUS FASCIATUS, Pr. Max. 



Peroffnaiiivs faseiatus, PK. MAX, Nora Acta C. L. C. Acad. XEX, i, 1839, 369; tab. xxxiv. IB. Eeise innere Nord- 



Amerika, I, 1839, 449. 



WAONER, Wiegmann's Archiv, 1841, H, 45. la Snppl. Schrcb. Ill, 1843, 612. 

 LECONTJS, Pr. A. N Sc. Phil. 1853, 224. 

 AVD. and BACH. N. Am. Quad., Ill, 1854, 341. 



Sp. Cn. Considerably larger than the honse mouse. Tail as long as the body without the head. Antitragns conspicu 

 ously lobed. Soles naked. Above reddish yellow, closely lined with black ; fore legs all rovmd, 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 

 coated 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 yellowisl 

 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 Princ< 

 Maximilian, (Chihuahua city, and the mouth of the Yellowstone,) I am unable to detect an) 

 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 ; th<; 

 naked soles are distinctly indicated in the diagnosis of the genus. 



A skin in the collection of the Philadelphia Academy, collected at Fort Eiley, Kansas, by 

 Dr. Hammond, agrees very well with this specimen > and with the description of Maximilian. 



