72 



NORTH AMERICAN FAUKA. 



[no. 3d. 



THOMOMYS PERPALLIDUS PERPES Merriam. 

 Lone Pine Pocket Gopher. 



(PI. V, fig. 3.) 



Thomomys aureus perpes Merriam, Proc. Biol. Soc. Washingtori, XIV, 111, July 19, 

 1901. 



Thomomys scapterus Elliot, Field Columb. Mus., zool. ser. Ill, 248, 1903. Tyi^e 

 collected by E. Heller, in Hanopee Canyon, Panamint Mountains, California. 

 Type specimen in Field Mus. Nat. Hist. 



Type. — Collected at Lone Pine, Owens Valley, Inyo County, Cali- 

 fornia, by E. W. Nelson, December 23, 1890. Type specimen in U. S. 

 Nat. Mus., Biological Survey collection. 



Distribution. — Upper Sonoran desert valleys and mountain slopes 

 of eastern California, from near head of Owens Valley south to Hes- 

 peria and Morongo Valley, into the valley of Kern River, and east to 

 the Providence Mountains, Cal., and the Grapevine Mountains, Nev. 

 (fig. 6). 



Characters. — About the size of perpallidus or slightly smaller, with 

 shorter tail, larger ears, slenderer skull, and brighter, stronger colors- 

 smaller and grayer than aureus; mammae in 4 pairs. 



Color. — Summer pelage: Upperparts bright buffy ochraceous; nose 

 grayish brown; ear patch dusky; underparts buffy or creamy white; 

 throat often pure white; feet and tail thinly covered with short 

 silvery hairs. Winter pelage: Upperparts duller, darker, and more 

 grayish buff. Young, very similar to adults. 



SJcull. — Slender and light with rarely a trace of lateral ridges; well 

 arched; narrower and slenderer than in perpallidus, with especially 

 slenderer rostrum; palate slightly more arched than in perpallidus, 

 much less arched than in aureus; interparietal generally quadrate; 

 bullae full and rounded; nasals slightly emarginate or occasionally 

 truncate. Dentition rather light; upper incisors decurved at right 

 angles to axis of skull. 



Measurements. — ^Average of 5 topotypes ( c? ad.) : Total length, 

 215; tail vertebrae, 66; hmd foot, 28.7. Average of 5 topotypes 

 (9 ad.): 210, 67, 28.5. SMll (of type): Basal length, 33; nasals, 

 12.3; zygomatic breadth, 22; mastoid breadth, 18.6; interorbital 

 breadth, 6.5; alveolar length of upper molar series, 7.5. 



RemarJcs. — This small gray foim of the perpallidus group occupies 

 Upper Sonoran desert valleys and slopes of eastern California. In 

 parts of the Mohave Desert where it extends down mto Lower 

 Sonoran vaUeys it becomes slightly larger and paler than normal and 

 might almost as well be placed with aureus; while in the foothills of 

 the Sierra Nevada, San Gabriel, and San Bernardino Mountains it 

 becomes shghtly darker than the typical form and may grade into 

 awahnee. It does not occur in Death Valley or Panamint Valley, 



