14 ZOOLOGY. 



THOMOMYS FULVUS. 

 PLATE XII, FIG. 2. 



Geomys fulvus, WOODHOUSE, Pr. A. N. Sc. Phil. VI, Dec., 1852, 201. IB. SHgreaves Exp. Zuiii and Colorado, 1853 



51 ; pi. v, Mammals. 



Pseudostoma (Geomys) fulvus, Ai D. & BACH. N. Am. Quad. Ill, 1854, 300. 

 Thomomys fulvus, BAIRD, Gen. Rep. Mammals, 1857, 402. 



SP. CH. Cheek pouches moderately large, well clothed with hair. Tail nearly half as long as the body, thick at base. 

 Extremities large. Claws large, not much curved. Third claw of hand 4 lines long above ; beneath, extending over two-sixths 

 the whole hand ; its digits about two-ninths the same length. Claw of the third reaching to two-fifths of the hand. 



Color. Above and on the sides, bright uniform reddish brown; beneath, yellowish white, with a tinge of chestnut on the belly. 

 Pouches white at the bottom, chestnut around and in the margins, chin dusky. Tail white ; dusky above at the base. 



A specimen, (No. 155,) was collected at camp 99, Picacho mountains, New Mexico, and others 

 were seen on Bill Williams Fork, San Francisco mountains, &c. 



PDIPODOMYS OKDII, W o o d h o u s e .Kangaroo Rat. 



BAIRD, Gen. Rep. Mammals, 1857, 410. 



In removing the cloth which was used in our tent as a carpet, at Camp 111, this animal was 

 found under it. No hole was observed in the ground within the tent, whence it could, have 

 come. When pursued it leaped wildly about, making at each bound an astonishing distance. 

 The specimen was lost on the Isthmus. 



? PEROGNATHUS PENECILLATUS, Woodhouse. 



BAIRD, Gen. Rep. Mammals, 1857, 418. 



A specimen, probably of this species, was collected at Camp 125, on Bill Williams Fork. It 

 was lost on the Isthmus. 



HESPEROMYS TEXANUS, Woodhouse .Texas Mouse. 

 PLATE VIII, FIG. 1. 



texaiia, WOODHOUSE, Pr. A. N. Sc. Phila. VI, February 1853, 242. IB. Sitgreaves Rep. Exp. Zufii, &c. 



1853, 48; pi. ii, Mammals 



Hesftcromys tixanus, BAIRD, Gen Rep. Mammals, 1857, 4^4. 

 Arcicolu (Hcsperoinys) tcxana, AUD. & BACH. N. Am. Quad. Ill, 1854, 319. 



SP. CH. Size and proportions about as in H. hucopus. Ears small; tail rather shorter than head and body. Color above, 

 reddish brown ; brighter than in H. Icucopus, and more like H. aureolas, but darker. No conspicuous wash of dusky on the 

 back. Feet, belly, and under surface of tail pure white. Outside of fore leg like the back ? 



A specimen of this species was obtained on the Pecos river, Texas. Many other long-tailed 

 mice, of several species, were collected at different parts of our route, but as all were lost on the 

 Isthmus, it is impossible to identify them. One of these (No. 107, a, collected at Camp 96,) 

 resembled the common white footed mouse, but was larger, the ears also larger in proportion. 

 Its abdomen was white, the same color extending slightly on each side ; the feet were perfectly 

 white ; the tail very long and hairy. It lived in the hollows of the cedar trees, like the Neotoma, 

 and also built up around the root of the tree a pile of small dry twigs. Sometimes as many as 

 three were found living together in the same tree. 



From, the characters of size, long tail, and general habits, it is probable that this is the Hes- 

 peromys calif ornicus, BAIRD, Gen. Rep. Mammals, 478, or a closely allied species. 



