Descriptions of Xiue New Mammals. 171 



three specimens have been received from Mr. Nelson from 

 Colima City and Armeria, Colima, and from Plantinar and 

 Zupotlaii, Jalisco. 



Color. Upper parts uniform drab-gray, slightly grizzled with 

 black-tipped hairs and faintly tinged with tawny, precisely as 

 in .17" * niiixrtil.iis; under parts buffy, the basal part of the hairs 

 plumbeous, without sharp line of demarkation ; tail above, con- 

 color with back ; slightly paler below. 



Cranial and Dental Characters. Skull similar to that of S. tay- 

 /o/v', but larger; first and second upper molars relatively shorter 

 and thicker ; anterior cusp of first upper molar not distinctly (if 

 at all) bi-tuberculate when young ; in S. taylori it is conspicu- 

 ouslv bi-tuberculate. 



<;<'n HX Arvicola. 



Mr. Nelson, obtained a series of 18 specimens of a new 

 species of Arvicola on the Sierra Nevada de Colima, in the state 

 of Jalisco, Mexico, during the latter part of April, 1892. The 

 species belongs to the western section of the subgenus Mynomes 

 (characterized by lacking the postero-internal loop of the middle 

 upper molar) and is related to Arvicola mogotlonensis of Mearns 

 from the pine plateau region of Arizona, but is larger, with the 

 tail and hind feet longer, and is much darker in color. It differs 

 also in cranial characters. 



Arvicola phaeus sp. nov. 



Type No. I? 40 ? ad. U. S. National Museum (Department of Agricult- 

 ure collection). From north slope of the Sierra Nevada de Colima, Jalisco, 

 Mexico (altitude, 10,000 feet), April 21, 1892. Collected by E. W. Nelson- 

 (Original number, 251<>.) 



Measurements (in millimeters, taken in flesh by collector). 

 Total length, 155; tail vertebra, 34; hairs, 4; hind foot, 20 J : 

 ear from anterior root, 14 (in dry skin). 



Color. Upper parts dark bistre, grizzled, and thickly inter- 

 spersed with long black;tipped hairs ; under parts plumbeous, 

 more or less washed with dilute tawny-drab ; tail indistinctly 

 bicolor, sooty above, paler below. 



