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



THOMOMYS DOUGLASSII. 



Coin Go pher. 



Geomys douglaxrii, RICH. F. Bor. Am. I, 1829, 200 ; pi. xviii, C, fig. 1-6. (Skull.) IB. Zool. of Blossom, 1839, 12. 



' LKCONTE, Pr. A. N. Sc. Phil. VI, 1852, 162. 

 Asxmys douglassii, WAGNBK, Suppl. Schreb. Ill, 1843, 392. 

 Pteudottama douglatsii, ADD. & BACH. N. Am. Quad. Ill, 1853, 24 ; pi. cv. 

 Thamomys douglatsii, GIEBKL, Saugt. 1855, 531. 

 Geomys fuliginonu, Scmsz, Synop. Mamm. II, 1845, 36. 



g p CH Cheek pouches large ; sparsely haired on the outer wall. Tail, one third to nearly one half the body. Upper 



iucisors nearly plane in front, with a distinct and sharp groove. Hand large ; claws very lartje and stout ; palm and digits 

 very short. Middle claw 5J lines above ; below, occupying nearly two-fifths of the hand ; its toe about two-eighths. First 

 finger or thumb very short, barely reaching over two-sixths the hand. 



Qjor. Above, dusky chestnut brown, but slightly mottled on sides and beneath with an ashy brown tinge. Cheek 

 pouches whitish at the bottom, the line of demarcation indistinct, and the brownish color of the marginal region running 

 down into the pouch. Tail grayish ; dusky above. 



This species has the depressed form of body, without indication of neck, &c., of the genus. 

 The ears are quite large, being distinctly evident as a margin to the auditory aperture. The 

 whiskers are short and white ; the cheek pouches ample ; scantily furred within, especially on 

 the side opposite to the jaws. The incisors are yellow, plane in front, or only rounded at the 

 edges ; the inner edge of the upper ones with a distinctly marked and sharp though delicate 

 groove, differing decidedly in the flatter incisors and distinctness of groove from T. bulbi- 

 vorus. The tail is moderate, contained nearly three times in the length of the body ; it is 

 depressed and somewhat flattened at the tip, and well covered with short stiff hairs. The fur 

 is fine, soft, and silky. The feet are large and strong ; the forefeet with the claws much curved, 

 compressed, trenchant, and long. The thumb is unusually short, almost rudimentciry ; the tip 

 of its claw not extending to the fissure between the second and third, and barely to the end of 

 the bulb of the fifth. The third claw is, as usual, the longest, and of great development ; it 

 occupies nearly two-fifths of the total length of the hand from the posterior part of the tubercle. 

 The palm and fingers are, however, unusually short, the third claw extending beyond the bulb 

 one-fourth longer than the length of this finger, which indeed is contained nearly four times in 

 the total length of the hand. The second and fourth claws are about equal ; the tip of the fifth 

 does not reach quite to the end of the bulb of the fourth finger. On the hind foot the third 

 claw extends furthest ; the second is a little longer than the fourth, and the first than the fifth. 



The upper parts are of a reddish or chestnut brown, not appreciably darker on the back ; 

 brightest and clearest along the occiput. On the sides and beneath, the lead colored bases of 

 the hairs are exhibited to a considerable extent, the ends tipped with pale grayish or ashy 

 reddish brown ; anteriorly, on the throat, between the foie legs and region around the cheek 

 pouches, the prevailing tint is a purer grayish ash. The edge of the lips and the top of the snout 

 are dusky, but the pouches are whitish on the inside near the bottom and do not exhibit the 

 sharp and decided contrast of white and dark brown seen in T. bulbivorus. The region behind 

 the ear is dusky. The feet are dull grayish white ; the tail is similar, with a dusky line along 

 a part of the upper surface. 



The fur exhibits little mottling with dusky ; the sides being nearly plain, thus differing 

 considerably from T. bulbivorus. The sides are more ashy and the under parts with less red. 



