464 PROCEEDINGS OF THE NATIONAL 3IVSEVM. vol.47. 



Color. — Adult in full winter 'pelage (186476, St. George, Utah, Jan- 

 uary 4; type) : Similar to corresponding pelage of ferpallidus; slightly 

 darker than in pulcher. Adult in spring (28359, Panaca, Nevada, 

 May 20) : Like winter pelage, but brighter, more ochraceous-pinkish- 

 buff. Juvenile (26653, Vegas Valley, Nevada, March 15) : Very pale; 

 like young of pulcher, but even paler, more drab-gray. Post-juvenile 

 pelage (28360, Oasis Valley, Nevada, June 2; in second year) : Almost 

 precisely like corresponding pelage of pulcher. 



STcull. — Palate never ending posteriorly with projecting spine; 

 usually truncate, rarely concave. Anterior palatine foramina short, 

 not reaching (or rarely in some intermediate specimens just reaching) 

 plane of front of first molars. 



Measurements. — Averages and extremes of 23 adults from Utah, 

 Nevada, and California: Total length, 141 (130-155) millimeters; tail 

 vertebrc^, 49.6 (40.0-58.0); hind foot, 19.9 (19.0-21.0); ear from 

 notch in dry skin, 14.2 (13.2-15.6). Skull: Condylobasal length, 22.8 

 (21.8-23.8); zygomatic breadth, 12.9 (12.7-13.3); interorbital 

 breadth, 4.9 (4.5-5.0); breadth of braincase, 11.6 (11.1-12.2); length 

 of nasals, 9.2 (8.6-9.9) ; length of mandible, 13.3 (12.5-14.2) ; max- 

 illary tooth row, 3.6 (3.4-3.8). For detailed measurements of speci- 

 mens see page 481. 



Type-specimen. — No. 186476, United States National Museum. 

 Skin and skull of adult male in full winter pelage. Collected by Ver- 

 non Bailey, January 4, 1889. Original No., 476; Merriam collection, 

 skin 5201, skull 5896. 



RemarTcs. — This subspecies is sharply separated from perpallidus 

 on the south by the Colorado River. At the type-locality it is com- 

 paratively dark, and is virtually indistinguishable in color in some 

 pelages from perpallidus, but the cranial characters are diagnostic 

 and rehable. Toward the v/est it gradually becomes more ochraceous 

 in color until* it meets and blends with the Owens Lake form on the 

 western slopes of the Argus Mountains. It also blends imperceptibly 

 into the paler form later described as pulcher, in the mountains bor- 

 dering the main Mohave Desert on the north. 



Specimens examined. — Total number, 65, from the following locali- 

 ties: 



Utah: St. George, 3 (including the type). 



Nevada^: Ash Meadows, 2; Bunkerville, 2; Carson Sink, 2; 

 Charleston Mountains, 2; Colorado River, southwest of Stone's Ferry, 

 2; Oasis Valley, 4; Pahranagat Valley, 1 ; Pahroc Spring, 3; Pahrump 

 Valley, 8; Panaca, 1; St. Thomas, 2; Stone's Ferry, 1; Table Moun- 

 tain, 1 ; Vegas Valley, 6. 



1 For an account of most of the obscure localities in Utah, Nevada, and Inyo County, California, listed 

 In this paper see a List of Localities Visited by the Death Valley Expedition, by T. S. Palmer, North 

 American Fauna, No. 7, pp. 361-384. 



