if 



W'l :■!. 



fl 



§ 





620 



MONOOUAPU8 OF NOllTn AMERICAN KODENTIA. 



arc scattered over the tail, and more evident ones clothe the instep ; but the 

 parts always present a peculiar skinny appearance. Tail less than one-fburtii 

 as long as the head and l)ody; han<lsnot as long ns the feet; smaller and weaker 

 than in tiie burmrhis group; ciieek-|)ouche8 arc not so liighly dcvelo|)ed. As 

 well as can be judged from prepared skins, the sacs do not reach to tiio 

 siioulder; their capacity, in an individual nearly a foot long, seems no greater 

 iliun that of specimcus of G. bursarius not more limn half as bulky. The 

 external meatus of the car has a small flap. The hisjnd pelage is a remark- 

 able feature, being coarse and harsli, almost entirely lustreless, longer than 

 usual, and interspersed witli still h)ngerand almost bristly hairs; and the color 

 is uniform to the roots of the hairs. It is clmmctcristic of all the soft-haired 

 species of Geomys to have plumbeous-colored fur at base, pointed with the 

 particidar l)rown, fulvous, or other shade which determines the appearance to 

 the eye. In G. hUpidux, the hairs are unicolor from base to tip; dark mahog- 

 any-bfovvn, or rather chocolate, <i little lighter or 'ir'vcr according to age or 

 season, or fortuitously, but uniform over all the upper parts and sides. Under- 

 neath, the color is paler, like cafe au hit ; sometimes quite smoky-gray or 

 muddy-brown. The under parts frequently show indeterminate patches of 

 wTiite. It is probable that plumbago-colored individuals occur, but I have 

 seen none such. The naked parts appear to have been reddish or flesh-colored ; 

 claws horn-color; incisors faced with red. 



• Note on a skull. 



In preparing the original memoir, I regretted that I had no skull of 

 either of tiiu Mexican s,)ecies to describe. Since thcti I have found a defective 

 specimen in tlie collection of the National Museum, marked "hispidus — Mex." 

 It is much larger than any United States specimen I have seen, measuring in 

 total length (from occipital crest to incisive alveoli) 2.70 inches, with a width of 

 1.85 across the wjdest part of the zygomatic arches. (A good-sized speci- 

 men of G. burxarius measures in the same dimensions 2.25 X 1 ••'>0.) Greatest 

 depthof skull.without jaw, 1.18(op|)osite premolars; the eorres|H)nding dimen- 

 sion of G. hurmrim is only 0.70). Width across occiput, 1.65. Length of 

 lower jaw .(condyle to incisive alveolus), 1.80 (in G. bursarius, 1.45) ; great- 

 est divergence of rami of the jaw (at the exflected angles), 1.80. The enor- 

 mous under incisors protrude more than an inch — 1.25 ; the upper incisors 

 arc cxserted for 0.G5. Tlie zygomalic width is increased by a well-marked 



