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



GEOMYS BREVICEPS, B a i r d . 



Short-headed Gopher. 



Geomtjt brevicyt, BAIRC, Pr. Ph. Acad. Nat. Sc. VII, April, 1855, 334. 



SP. CH. Upper incisors with a small groove near the inner edge, and a much larger one bisecting the remaining space. 

 Fore feet decidedly longer than the hinder ones. The second claw reaching half way down the fourth. Check pouches 

 quite ample. 



Colors. Above, dark chestnut brown, with cloudings caused by darker tips to the hairs. Beneath, paler, mixed with 



grayish. Inside of pouches and surrounding region entirely yellowish white. Skull short, broad. Forehead plane. 

 Outline of zygomata, as viewed from above, curved ; separated most widely at the junction of malar and temporal. 



This species, from the indications afforded by the skulls of the two specimens under exami 

 nation, is much the smallest of those with bisulcate incisors. The ears are quite obsolete in 

 one specimen ; in another, rather more distinct than usual in this group of Geomys, the 

 encircling ridge of skin being quite prominent. The whiskers are very short. The cheek 

 pouches are large and deep, amply coated wi^h hair everywhere. The tail is contained between 

 two and three times in the length of the body. It is scantily coated with hair, most densely 

 near the base. The fur is moderately full and soft, more so than in G. bursarius. 



The furrowing of the incisors is much as in G. bursarius from St. Louis. The inner groove 

 is, however, somewhat narrower and shorter. The main groove bisects the portion exterior to 

 the inner groove, the halves being symmetrical and rounded. 



The fore feet or hands are but little longer than the hind feet ; their claws are very large and 

 stout. The middle claw, measured above, reaches from the end of its finger to the tubercle of 

 the palm ; its under surface occupies a little more than one-third of the whole hand. The first 

 finger is very rudimentary, its claw only reaching over about one-third the hand, and extend 

 ing barely to the end of the fifth finger. The second finger is considerably shorter than the 

 fourth, and its claw only reaches to about the middle of the fourth claw, and to the end of the 

 third finger. The fifth claw extends beyond the end of the second finger. On the hind feet, 

 the first and filth toes are almost rudimentary, especially the latter. The claw of the fifth 

 reaches to the base of the first claw ; the second claw reaches to the end of the third toe ; the 

 fourth claw a little beyond the base of the second. The second claw is about as long as the 

 third, and widened at the end. 



The color is not markedly different from the St. Louis species. The upper parts are of a dark 

 chestnut brown ; the ends of the hairs tipped with still darker along the middle and posterior 

 portion of the back, imparting an indistinct clouding to the color. The under parts are of a 

 paler tint of the same mixed with greyish, and showing a good deal of the plumbeous bases of 

 the hairs. 



The inside and edges of the cheek pouches, lips, chin, throat, hands and posterior edge of 

 the fore legs, are of a uniform yellowish white, perhaps quite white when not altered by alcohol. 

 The tail is obscurely white beneath and dusky above. 



