162 Merriam New Genus and Species of Murinc Rodent. 



less distinct one under each ear ; color of upper parts rich ful- 

 vous; under parts white ; ears about half as long as the head 

 and nearly naked (sparsely clothed with fine, inconspicuous 

 hairs) ; whiskers reaching back to shoulders ; fur soft. 



Color. Upper parts fulvous or tawny-rufous, palest on the 

 head and brightest over the rump, flanks, and hips ; back 

 sparsely mixed with black-tipped hairs ; an ill-defined dusky 

 ring around each eye, above which is a whitish spot about as 

 large as the eye itself; a less distinct whitish spot just below the 

 inferior root of the ear ; upper lips white, the white color extend- 

 ing up on the cheeks more than half way to the eyes ; sides of 

 face below eyes and ears washed with fulvous, whiskers black- 

 ish ; tail concolor. dark umber-brown all round ; upper surfaces 

 of feet whitish, more or less clouded with dusky (varying con- 

 siderably in the three specimens) ; under parts creamy white to 

 the very roots of the hairs except along the sides of the belly, 

 where the basal part of the fur is plumbeous ; line of demarka- 

 tion between colors of upper and lower parts everywhere sharp 

 and distinct. 



An immature but full-grown specimen from Armeria, Colima 

 (collected March 2, 1892), has a small whitish lanuginous tuft 

 in front of the anterior base of each ear, in addition to the mark- 

 ings of the specimens from Hacienda Magdalen a, already de- 

 scribed. This may be characteristic of the winter pelage. The 

 same specimen has white feet, and the white of the face is more 

 extensive. 



Cranial Characters. The principal cranial peculiarities have 

 been pointed out in the generic description. The great size 

 of the audital bulla? is doubtless a specific character, though not 

 the direction of their axes. The bullte are broader anteriorly 

 than posteriorly, and curve slightly outward in front of the 

 meatus, where the inflated portion is much more extensive than 

 that behind it. The large size of the interparietal also is in all 

 probability a specific feature. In one of the three skulls its 

 antero-posterior diameter along the median line equals that of 

 the parietals. The ascending branches of the prcinaxillaries 

 reach as far back as the nasals, which end on a line with the 

 lachrymals. 



Dental Characters. (The generic characters already mentioned 

 are not repeated here.) First upper molar with crown more 

 than half as broad as long; outer side straight; inner side 



