110 



ZOOLOGY. 



Genus PEROGNATHUS, Maxim. 



PEEOGNATHUS PEN1CILLATUS, Wooilli. 



Tufit-iailed Kangaroo Mouse. 



rirognatltvs penitillatus, WooDn., Proc. Acad. Nat. Sci. Phila., 1852, 200; Sitg. Sep. 

 ICxpl. Znfii & Colorado E., 1853, 49, pi. 3. AUD. & BACH., Q. N. A., iii, 

 1854, 298. BAIED, M. N. A., 1857, 418, pi. 20, f. 5. COUES, Arn. Nat., i, 

 18G7, 397. GRAY, P. Z. S., 18GS, 201. COUES, Proc. Acad. Phila,, 1875, 287 

 (monographic). 



Originally described from the region embraced in the present report, 

 of which it is a characteristic species. 



Other individuals of this genus, or of Cricetodipiis, were secured as indi- 

 cated below, but have not as yet been identified. 



Specimens. 



? PEEOGNATHUS MONTICOLA, Baird. 



Fcrognatlnts monticola, BAIIJD, M. N. A., 1857, 422, pi. 51, figs. 3 -/;, SUCKL., P. E. E. 

 Eep., xii, pt, ii, I860, 101 COUES, Proc. Acad. Nat, Sci. Phila., 1875, 293. 



AVe refer to -this species, with some doubt, two specimens collected by 

 Mr. Henshaw on Otter Creek, Utah. These are apparently young animals, 

 but, as they are not accompanied with the skulls, the point cannot be de- 

 termined. Owing to their taxidermal condition, the relative proportions of 

 body and tail cannot now be ascertained. The specimens are quite small ; 

 in a somewhat over-stuffed condition, they measure about 2i inches, but were 

 probably little, if any, over 2 inches from nose to root of tail ; hind foot 

 0.80 ; and in fact they resemble, at first sight, a species of Cricetodipus rather 

 than of Peroynatlms. But the soles are naked, along a narrow strip, quite 

 to the heel ; the antitragus has a prominent lobe ; and we determine, with- 

 out appreciable risk of error, that the ear has the peculiar structure of P. 

 monticola. The pelage is remarkably soft ; the coloration is different from 

 that of any other PerognatJtus we have seen, being plumbeous, with little 



