504 MONOGRAPHS'OF NORTH AMERICAS RODENTIA. 



M \ series of specimens does not suffice for a complete exposition of (lie 

 variation in color of this species. In all, the lateral stripe is conspicuous, and 



the other characters differ little 1 note, however, a decidedly richer tone 

 in Mexican and Texan specimens than ill those from Kansas and Nebraska. 

 It is probable that the skull of this animal, when examined, will afford some 

 specific characters, in size at least, if not in details of conformation. The 

 venerable Dr. G. Lincecum, of Texas, lately deceased, has given notes on the 

 habits of this species, in two special articles, below cited.* 



PEROGNATHUS PENICILLATUS, Woodh. 



Tuft-tailed Pocket-mouse. 



rerot/nalhus }H)ici:illatus, W<)ODH.,t Proc. Acad. Nat. Sci. Phila. vi, 1853,200 (San Francisco Mts., Arizona). 



Peroguaihus penicillatus, WOODH., Sitgreaves's Rep. Expl. Znfii and Col. R. 1853, 49, pi. 3. — LkC, Proe. 

 Acad. Nat. Sci. Phila. 185;!, 225 (mure mention).— Add. & Bach., Q. N. A. iii, 1854, 298 

 (copied from Woodh.).— Bl>., M. N. A. 1857, 41H, pi. CO, f, 5.— GlJAY, P. Z. S. 1868, 201 (wrong 

 locality assigned) t — Coues, Am. Nat. i, 1867, 397 (Arizona). — Couiss, Proc. Phila. Acad. 

 1875, 287 (monographic).— Cocks A Yaerow, ZooI.Expl. W. 100 Merid. 1875, 110. 



Perognalhm parvus, LeContb, Pioc. Acad. Nat. Sci. Phila vi, 1853,225 (in part. Not Cricetodipus parvus, 

 Peale.) (The specimen noticed from the Colorado Desert is now before me ; it is apparently 

 a very young example of /'. -penicillatus.) 



Diagnosis. — About the size of Ilespproniys leucopus. Tail vertebrae obvi- 

 ously longer than head and body. Hind foot more than one-fourth the length 

 of head and body. Tail crested above toward the end, and with long term- 

 inal pencil of hairs. Soles distinctly naked to the heels, at least along a 

 median strip. Antitragus distinctly lobed, with a sharp teat-like projection, 

 opposite which is another smaller but distinct lobe of the tragus, the notch 

 of the ear being defined by these two prominent points, the edge of the ear 

 itself not bounding the notch at all. No appreciable fulvous stripe along the 

 sides, where the color of the upper parts meets the white of the under parts 

 without intervention of a third color. Above, "gray" — an intimate mixture of 

 yellowish-gray with a dull grayish-brown; below, including whole fore leg, 

 fore and hind feet, and inner aspect of thighs, white ; tail bicolor — dark above, 

 white below. Length about 3.25 inches (2.9J-3 60); tail vertebra about 

 4.00 (3.50-4.40), with a tuft half an inch or more longer. Soles about 0.95 

 (0.90-1.00); ear above notch, 33 (0 30-0.35). 



"Pouched Rat. < Am. Nat. vi, 1^72, pp. 369, 370. 

 The Animals of Texas. < Amer. Sportsman (newspaper) of Feb. 28, 1874. 



t Special paper: " Description of a new species of Perognathus, Wied." < loc. cit., pp. 200,201. 



! The San Francisco Mountains are several hundred milts from San Francisco City, California, 

 nearly in the middle of Arizona — formerly a part of New Mexico. The locality appears to puzzle some 

 writers. 



