248 FIELD COLUMBIAN MUSEUM ZOOLOGY, VOL. III. 



and thighs; orbital ring black; entire under parts, hands, and feet 

 white; base of fur on sides only, plumbeous; tail above like back, 

 slightly darker towards tip, beneath yellowish white; ears naked, dark 

 brown; soles of feet naked. 



Measurements: Total length, 360; tail vertebrae, 150; hind foot, 

 40; ear, 33.5. Skull: total length, 45.5; Hensel, 40; zygomatic 

 width, 25; interorbital constriction, 6; width of brain-case above 

 roots of zygomata, 19; palatal length, palatal arch to alveolus of 

 incisor, 22; length of upper tooth row, alveolar border, 9; length of 

 mandible, angle to tips of incisors, 31; length of lower tooth row, 

 alveolar border, 9. 



This wood rat is of a very much paler color than T. cinerea, the tail 

 being especially noticeable for its light hue when placed among speci- 

 mens of the typical form. The skull presents no differences worthy of 

 remark. This rat was procured by Mr. Heller at high elevations, 

 8,000-11,000 feet on Mt. Whitney, and on the Inyo Mountains, the 

 higher range being on the last named, where it was more numerous at 

 timber line. 



FAM. GEOMYID^:. 



THOMOMYS. 



Thomomys *scapterus. Sp. nov. 



Type locality: Hannopec Cafton, Panamint Mountains, Inyo County, 

 California. 



Geogr. distr.: Panamint, Inyo and Coso mountains, Inyo County, 

 California. 



Gen/, char.: Similar to T. operarius, but much darker in color, 

 and with much shorter nasals. 



Color: Upper parts and side wood brown, heavily lined with black 

 on top of head and dorsal region, in some specimens nearly forming a 

 dorsal band, but in the type this part is more uniform with the side, 

 'the back being less heavily lined with black; lower sides and entire 

 under parts white, the plumbeous under fur showing through; hands 

 and feet whitish; tail unicolor, white; ears and small spot behind ear 

 black. 



Measurements: Total length, 229; tail vertebrae, 74; hind foot, 29; 

 ear, 6. Skull: total length, 37; Hensel, 33; zygomatic width, 23; 

 interorbital constriction, 6; greatest width of brain case, 9; palatal 



* sxanrqp a digger. 



