1915. ] 



THOMOMYS FOSSOR GROUP. 



113 



between; auditory meatus moderately large. Dentition relatively 

 light; incisors very long and slightly protruding. 



Measurements. — Type ( J ad.): Total length, 237; tail vertebrae, 

 71; hmd foot, 34. Topotype ( 9 ad.): 227, 68, 31. Average of 10 

 adult males: 244, 72, 33.2. Average of 10 adult females: 233, 71, 

 31.5. Ear: From crown, 8. Slcull (of type): Basal length, 39; 

 nasals, 16; zygomatic breadth, 24.5; mastoid breadth, 22; interor- 

 bital breadth, 7; alveolar length of upper molar series, 8. 



Remarlcs. — This big gopher is abundant in fertile valleys in 

 the Transition Zone, but does not inhabit the arid upland. It 

 is a strongly marked, outlying form of the jossor group, and its 

 nearest relative is uinta. It has a lower zonal range, however, and 

 seems to be entirely distinct. More thorough collecting may show 

 that it grades into uinta higher up the streams, but at present the 

 two are best treated as distinct species. 



At the type locahty females were found normally to have 10 

 mammae and 5 embryos, as contrasted with the 14 mammae and 7 

 embryos in the little ocius of the dry sagebrush mesas close by. 

 Specimens examined. — Total number, 74, as foUows: 

 Idaho: Montpelier, 18; Montpeiier Creek (6,000 feet altitude), 1. 

 Wyoming: Bear River (14 miles north of Evanston, 6,600-6,800 feet altitude), 

 5; Border, 1; Cokeville (6,400 feet), 8; Fort Bridger, 24; Henry's P^ork (5 

 miles west of Lonetree), 1; Lonetree (7,400 feet), 3; Lonetree (4 miles south), 

 2; Mountain View, 11. 



THOMOMYS UINTA Merriam. 

 Uinta Pocket Gopher. 

 (PI. vn, fig. 14.) 



Thomomys uinta Merriam, Proc. Biol. Soc. Washington, XIV, 112, July 19, 1901. 



Type. — Collected in Umta Mountains (10,000 feet altitude, north 

 base of Gilbert Peak), Summit County, Utah, by Vernon Bailey, 

 June G, 1890. Type specimen in U. S. Nat. Mus., Biological Survey 

 collection. 



Distribution. — Western Wyoming, southeastern Idaho, and northern 

 Utah (fig. 5). 



Characters. — About the size oi Jossor and practically indistinguish- 

 able in external characters; skull shorter and wider, with shorter 

 rostrum and heavier dentition; mammae in 5 pairs, inguinal 2-2, 

 pectoral 3-3. 



Color. — Summer pelage: Upperparts dull dark brown, with dusky 

 nose and face and blackish ear and ear patch; underparts buffy or 

 ochraceous, mth occasionally a white patch on chin; feet and tip 

 of tail usually whitish. Late Jail and winter pelage: Duller and more 

 grayish. Young, paler, more huffy than adults. 

 98121°— 15 8 



