1915. ] 



THOMOMYS FOSSOB GROUP. 



115 



Slcull. — Relatively short and rectangular, with parallel lateral 

 ridges, and rectangular zygomatic arches; nasals short and pos- 

 teriorly truncate; pterygoids V-shaped; interparietal smaU, rounded, 

 triangular, or cordate; buUse rather smaU. 



Measurements. — Average of 3 male topotypes: Total length, 210; 

 tail vertebrae, 64; hind foot, 27. Average of 5 female topotypes: 

 195,62,26.4. Slcull (of type) : Basal length, 36; nasals, 13.5; zygo- 

 matic breadth, 24; mastoid breadth, 19; alveolar length of upper 

 molar series, 8. 



Remarks. — This is a wide-ranging, variable form of the fossor 

 group, occupying the Upper Sonoran plains of eastern and central 

 Oregon, northeastern Cahfornia, and northern Nevada, and extending 

 higher up in some of the narrow desert ranges. 



Specimens examined. — Total number, 159, as follows: 



Calif omia: Bieber, 7; Brownell, 1; Dry Creek (at 4,450 feet altitude), 1; Eagle 

 Lake, 2; Goose Lake, 1; Goose Lake Meadows (4,800 feet), 2; Lake City, 1; 

 Lassen Creek, 7; Madeline Divide, 1; Madeline Plains, 6; Pete's Valley, 1; 

 Secret Valley, 1; Sugar Hill (Modoc County, 5,000 feet), 1; Susanvllle 

 (4 miles south), 2; Warner Mountaius (head of Parker Creek, 7,300 feet), 16; 

 Wai-ner Mountains (Parker Creek, 5,500 feet), 13; Warner Peak (east slope, 

 8,700 feet), 3. 



Nevada: Badger, L 



Oregon: Adel, 4; Crooked River, 3; Fremont, 4; Harney, 2; Ironside (4,000 

 feet altitude), 11; Lake Alvord, 1; Lakeview, 4; Matoleus River, 2; Merrill, 2; 

 Moimt Warner, 1; Shirk, 17; Silver Lake, 6; The Dalles, 21; Tumtum Lake, 

 1; Wapinitia, 1. 



Washington: Rockland, 12. 



THOMOMYS QUADRATUS FISHERI Merriam. 



Fisher Pocket Gopher. 



(PI. Vn, fig. 16; text fig. 3.) 



Thomomys fuscus fisheri Merriam, Proc. Biol. Soc. Washington, XIV, 111, July 19, 

 1901. 



Ty^^e.— Collected at Beckwith, Sierra Valley, Plumas County, 

 California, by W. K. Fisher, August 3, 1900. Type specimen in U. S. 

 Nat. Mus., Biological Survey collection. 



Distribution. — Northern, central, and western Nevada; west in 

 California to Sierra Valley and Mono Lake (fig. 6). 



Characters. — Slightly smaller than quadratus, shorter-tailed, and 

 paler; smaller than clusius, about the same color but with narrower 

 skull and smaUer bull^.; much larger than idahoensis with relatively 

 smaller bullae; claws moderately stout; mammae in 5 pairs, inguinal 

 2-2, pectoral 3-3. 



Color. — Summer pelage: Upperparts buffy gray, lightly washed 

 with dull russet over back; ear patch blackish; nose plumbeous; 

 underparts buify; chin white; feet whitish; tail whitish below, gray 



