386 U. Ss. P. R. R. EXP, AND SURVEYS—ZOOLOGY—GENERAL REPORT. 
The only species with incisors, similarly grooved, to which this approaches at all, is the @. 
clarkii, of Western Texas. The differences in color are at once appreciable ; the former having 
the well-defined patch on each side of the face; the latter colored uniformly over the whole 
back and sides. The claws of the hands are shorter, and the fingers longer, in G. castanops ; 
its hind feet are longer in proportion to the hands, and the second toe longer, its claw larger 
and more spoon-shaped. The skull is not so broad, nor is the expansion of the zygomatic arch 
at the junction of the maxillary process and the malar bone, so great. 
GEOMYS HISPIDUS, Leconte. 
Geomys hispidus, Leconts, Pr. A. N. Sc. Phil. VI, Sept., 1852, 158. (Mexico.) 
Pseudostoma (Geomys) hispidum, Avp. & Bacu. N. Am. Quad. III, 1854, 306, (from Leconte.) 
Sp. Ca.—Upper incisor probably with a single median furrow ; fore feet decidedly shorter than the hinder; second claw 
of hand reaches nearly as far as the fourth ; cheek poyches small; fur very stiff and coarse ; color, everywhere a uniform 
reddish brown or dark chestnut; the hairs the same color to their roots. 
This species, established by Dr. Leconte, is, as stated by him, quite conspicuous among all 
others by the great coarseness of the hair and its uniform color throughout. The hairs, in fact, 
are quite like bristles, and scattered thinly over the skin, with little or no softer fur intermingled. 
The ears are, as usual, very rudimentary. The upper incisors are broken off, but a careful 
examination of their stumps in the sockets shows them to have been broadly and deeply grooved 
down the central line ; there was probably no second internal groove. The pouches do not 
appear to have been very ample. 
The forefeet are rather shorter than the hinder ones ; the middle claw measured above is about 
as large as the hand to the tubercle, (the claw not included,) its under surface is contained 
nearly three times in the whole hand. The second and fourth fingers are nearly equal; the 
fourth claw rather longer, and decidedly stouter than the second. The fifth claw does not reach 
to the end of the fourth finger, (the claw excluded.) On the hind foot the disproportion between 
the first and fifth toes, and the second and fourth toes, is greater than usual; the first claw 
reaching even more than midway between the fourth and fifth, or even to the base of the former; 
the second again but little shorter or smaller than the third. The hand of this species is very 
similar in general appearance to that of Thomomys douglassii, The tail of the specimen, as 
prepared, is entirely naked. 
The color above and below is a nearly uniform reddish brown or dull chestnut, the hairs being 
of the same tint to their very roots. 
The only specimen I have seen of this species is in the rich cabinet of the Philadelphia 
Academy of Natural Sciences. It was collected by Mr. Pease, between Vera Cruz and the city 
of Mexico, during the late war, and is the original of Dr. Leconte’s description. 
