140 ^VTsjr MAM^^ALS fbom Mexican bobder—meaexs. vol.xix. 



Above drab-gray, inclining to fawn color on sides ; dorsal area with very 

 little admixture of black-ringed or black-tipped liairs; Avitb a conspic- 

 uous tuft of white hairs at anterior base of ear; dark spot on anterior 

 band of ear, drab (not black); whiskers more white tlum black; nnder 

 parts, feet, and end of tail, white; basal two-thirds of upper side crt" 

 tail, drab, some of the hairs with hoary tips. Length, 137 mm.; tail 

 vertebra', ~h^ (to end of pencil, ~u); ear from crown, 14; ear from notch, 

 17; distance between eyes, 10; diameter of eye, 4; longest whisker, 38; 

 from tip of nose to eye, 13; to center of pupil, 15; to ear, 1*1.5; to tip 

 of ear, 40; to occii)ut, 29; to end of outstretched hinder extremity, 133; 

 fore limb, measured from olecranon process to end of longest claw, 28; 

 length of fore foot, 13.4; longest daw of forefoot (chord), 3; hind limb, 

 measured from knee-joint to end of longest claw, 41; length of hind 

 foot, 21; longest claw of hind foot, 2.7. Skull, 25.5 by 13.5 mm. 



(rcofiraphic range. — Tliis is the counterpart and miniature of Oiiyeho- 

 mys pallescens, Merriam. The two are almost indistinguishable in color ; 

 and tlieir ranges are probably coincident. We found it only on the 

 Eio Grande near El Paso; but tliere is a specimen in the United States 

 National Museum (Xo. -^-A-), formerly included by Secretary Baird in 

 his "list of specimens" of '■'■Hesperomys texanxs,'''' which was collected by 

 Dr. Kenuerly, between the Pecos Piver and the Pio Grande. The speci- 

 mens of this species of OnychoDtys, taken by us west of the Eio Grande, 

 for the first hundred miles, are small-eared, but otherwise closely 

 resemble typical torridiis, to which subspecies they are nnhesitatingly 

 referred. 



ONYCHOMYS TORRIDUS PERPALLIDUS, new subspecies. 

 YUMA GRASSHOPPER MOUSE. 



Typc.So. 00174, XJ.S.X.M. (Coll. International Boundary Commis- 

 sion). Skin and skull. Adult female, from the left bank of the Colo- 

 rado Piver, at Monument Xo. 204, Mexican boundary line. Collected 

 by Edgar A. Mearns and E. X. Ilolzner, March 27, 1804, Original 

 number, 3301. (Has suckled young.) 



Description of type. — Larger than Onyelioniys /orn'rf^s (typica), with 

 relatively larger ears, longer tail, and a. mucli i)aler coloration. Color 

 above, drab-gray, becoming more cinereous anteriorly; sides and rump 

 barely tinged with fawn coh)r; dusky line on basal three-fourths of tail 

 much obscured by whitish hairs — nearly obsolete; ears less densely 

 clothed than in the remaining forms of Oiiyehoniystorritliis. -.[ud without 

 a well-<letined, dusky spot; wliiskers nu)stly wliite or colorless; under 

 parts, feet, and end of tail, white. Length, 157 mm, ; tail vertebra^, 57 ; 

 ear from crown, 16; length of hind foot, 22. Skull, 2G by 13.7 mm. 



GeoynipJiie ranye. — This subsi)ecies was first found on the lower Gila 

 River, at Gila City, on the east side of the Yuma Desert. Its range 

 extends thence westward across the Yuma and Colorado deserts to the 

 Coast Pange of mountains. In the direction of the San Bernardino 

 Valley, of California, it intergrades with the dark-colored Pacific Coast 

 form which Mr. Phoads has named rmnonu. 



