RODENTIA-GEOMYINAE—THOMOMYS BULBIVORUS. 
389 
Of these I am inclined to believe that Thomomys borealis may hereafter be referred either to 
T. douglassi or to T. rufescens. What other combinations may he required can only be ascer¬ 
tained hereafter. 
THOMOMYS BULBIVORUS. 
California Gopher. 
? Diplostoma bulbivorum, Rich. F. B. Am. I, 1829, 206 ; pi. xviii, B. (marked Diplostoma douglassi.) — Ib. Zool. of 
Blossom, 1839, 13. 
Geomys bulbivorus , Leconte, Pr. A. N. Sc. Phil. VI, 1852, 163. 
Pseudosloma bulbivorum, Aim. & Bach.. N. A. Quad. Ill, 1854, 337. 
Diplostoma douglassii, Rich. F. B. A. I, 1829, pi. xvii, B. (by error.) 
Orydomys ( Saccophoms) bottae, Eydoiix et Gervais, Mag. de Zool. VI, 1836, 23 ; pi. xxi, fig. 4, (molars.)—I b. 
Voyage de la Favorite, V, 1839, 23; pi. viii, f. 4, (molars.) 
Thomomys bottae, Lesson, Nouv. Man, R. An. 1842, 119. 
Baird, Pr. A. N. Sc. Phila. VII, April, 1855, 335. 
Sr. Ch.—C heek 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 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 hack. Beneath paler. Tail grayish white, except a short line of dusky along the base above. 
Chin dusky ; its extremity white. 
This species, although apparently the largest of its genus, does not appear to attain the size 
of Geomys bursarius, as the skull of a stretched skin nine inches long presented the appearance of 
extreme old age, in a distinct median longitudinal crest on the top of the head. The incisors 
are yellow ; the upper ones slightly convex transversely, with an obsolete furrow near the 
inner edge, the extreme edge being slightly raised into a ridge. The whiskers are short, and 
silver gray ; the ears, though short, are distinctly discernible, having an elevation of nearly 
a line. The body is cylindrical, or somewhat depressed ; the fur very soft, and rather short 
on the middle of the back, not exceeding four lines in length. The feet are quite small, and 
weaker than usual in this section. On the hand the third finger is longest; its claw, measured 
from beneath, occupies about one-third the entire length of the palm, and is a little longer 
than the toe itself, which, in turn, is nearly one-third the same length ; the second and fourth 
claws reach nearly the same length, the former a little the longer, extending beyond the 
middle of the third claw; the claw of the fifth finger extends to the bulb of the fourth ; the 
first finger is very short, its claw not reaching to the end of the fifth finger, nor quite to the 
base of the third, extending over about two-fifths of the palm. The palms are naked, and the 
fingers are all margined by a fringe of stiff gray hairs. The claws are all long, compressed, 
and slightly curved ; not acuminate at the end. The claws of the hind feet, as usual, are much 
shorter than those in front, broader and more spoon-shaped. The third toe is longest, the 
second little shorter, and longer than the fourth ; the first exceeding the base of the second toe 
and longer than the fifth. The soles are naked. The tail is moderately long ; about one- 
third the total length, covered throughout with close pressed hairs. The cheek pouches, too, 
are densely coated with short hairs, which do not exhibit the naked skin between. 
The upper parts and sides are of a rich chestnut brown, or dark cinnamon, finely and faintly 
