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 be required can only be ascer 

 tained hereafter. 



THOMOMYS BULBIVOKUS. 



California Gopher. 



f Diplostoma bulbivonim, RICH. F. B. Am. I, 1829, 206 ; pi. xviii, B. (marked Diplostoma douglassi.) IB. Zool. of 



Blossom, 1839, 13. 



Geomys bulbivorvs, LECONTE, Pr. A. N. Sc. Phil. VI, 1852, 163. 

 Fseudostoma buttrivorum, AUD. & BACH. N. A. Quad. Ill, 1854, 337. 

 Diplostoma douglassii, RICH. F. B. A. I, 1829, pi. xvii, B. (by error.) 

 Oryclmnys (Saccophorus) bottae, EYDOITX ET GERVAIS, Mag. de Zool. VI, 1836, 23 ; pi. xxi, fig. 4, (molars.) IB. 



Voyage de la Favorite, V, 1839, 23 ; pi. viii, f. 4, (molars.) 

 Thomomys bottae, LESSON, Nouv. Man. R. An. 1842, 119. 



BATED, Pr. A. N. Sc. Phila. VH, April, 1855, 335. 



Sr. Cn. 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 4 lines, 

 its under surface occupying about two-sixths the whole hand, its ringer 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, 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 



