MAMMALS. 
13 
color at base, then pale cinnamon white to cinnamon. Tail like the back, its tip black, with the hairs light colored at base. 
Length about 12 inches; tail, with hairs, 4 ; hind foot about 2.25 inches. 
This well known marmot we found very abundant throughout Texas, and on the Jornada del 
Muerto, of New Mexico. We did not observe it north of this district, nor did we find it west 
of the Rio Grande at all. However, it was found by Mr. Clark, near tbe copper mines of Santa 
Rita, and in other places west of the Rio Grande ; but the nature of the country over which we 
passed was of a nature unsuited to their habits, being too barren, and generally not affording 
vegetation of the kind upon which they feed. 
GEOMYS CLARKII, Baird.—Pecos Gopher. 
Geomys clarkii, Baird, Pr. A. N. Sc. Ph. VII, April, 1855, 332 .—Ib. Gen. Rep. Mammals, 1857, 383. • 
Sp. Ch.— Upper incisors with a single deep groove bisecting the surface, the portions on either side equal. Fore feet 
nearly equal to or rather shorter than the hinder ones. Second claw of the hand reaching as far as the fourth. Pouches small. 
Fur soft and full. 
Color above, uniform yellowish brown, the hairs with dusky tips. Beneath, paler and grayer. Cheek pouches much like the 
surrounding region. 
A fine specimen of this species was obtained on the Pecos river, Texas. 
THOMOMYS BULBIYORUS, Baird .—California Gopher. 
Plate XI. 
? Diplostoma bulbivorum, Rich. F. B. Am. I, 1829, 20G; pi. xviii, B, (marked Diplottoma douglassi.) —Ib. Zool of 
Blossom, 1839, 13. 
Thomomys bcttae, Lesson, Nouv. Man. R. An. 1812, 119. 
Baird, Pr A. N. Sc. Phila. VII, April, 1855, 335. 
Thomomys bulbivorus, Baird, Geu. Rep. Mammals, 1857, 389. 
Sp. Ch — Cheek pouches large, completely furred inside, white to their very margin, which is dark brown, forming a very 
strong contrast. Tail from one-third to less than one-half the length of body; slender at base. Upper incisors quite convex 
transversely; groove obsolete. Hands small; claws very slender and delicate, nearly straight; middle claw 4J lines, its under 
surface occupying about two-sixths the whole hand, its finger barely shorter than this; claw of thumb extending over two-fifths 
of whole hand. 
Color. —Reddish chestnut brown above and on sides, finely lined everywhere by dusky tips to the hairs, without any uniform 
dark wash on the back. Beneath paler. Tail grayish white, except a short line of dusky along the base above. Chin dusky; 
its extremity white. 
This species was observed in various parts of California, especially near San Francisco. 
THOMOMYS LATICEPS, B a i r d .-Broad-headed Gopher. 
Plate XII, Fig. 2. 
Thomomys laticeps, Baird, Pr. A. N. Sc. Phil. VII, April, 1855, 335. 
Ib Gen. Rep. Mammals, 1857, 392. 
Sp. Cii.—C heek pouches moderate, well haired. Tail nearly one-half the body, thick at base. Skull very broad and muzzle 
short; the upper incisors convex, the groove quite distinct. Feet very large and broad. Claws of fore foot or hand small, 
slender, 4 lines long above ; below, about two-sevenths the length of the whole hand, its digit about two-eighths. Claw of thumb 
extending over nearly three-sixths the hand. 
Color.— Above, yellow reddish brown; the dorsal region with the hairs largely and sharply tipped with blackish; sides nearly 
uniform; beneath, tinged with reddish. Pouches dull white, the dusky of the surrounding region dipping into them. Tail grayish 
white, dusky above. 
One specimen was obtained by Lieutenant Trowbridge at Humboldt Bay. 
