_Remarks._--Wah Wah Springs, the type locality of _wahwahensis_, are on the summit of a low pass in the Wah Wah Mountains in the desert of west central Utah. The surrounding valleys, for many miles, as far as my investigations show, are not inhabited by pocket gophers, except the Desert Range Experiment Station of the United States Forest Service in Pine Valley to the west of these mountains. There, pocket gophers were obtained which are intergrades between _centralis_ and _wahwahensis_. In five out of seven characters investigated these gophers resemble _wahwahensis_, to which they are here referred. Study of the topography reveals the probable means by which the animals reached this valley. The long axis of the Wah Wah Mountains is north and south, but a westward arm forms the northern boundary of Pine Valley. Around springs in this westward projecting arm workings of pocket gophers were found. With the development of water at the Desert Range Experiment Station, and subsequent improvement of forage, these animals probably came down into the valley from the springs to the north. The terrain between the Desert Range Experiment Station in Pine Valley and Snake Creek (where _centralis_ occurs) to the west is not inhabited by pocket gophers at present. This area, however, forms part of the southwest mainland of Pleistocene Lake Bonneville, which mainland in times past was probably suitable for pocket gophers. Since the close of the Pleistocene, aridity has rendered most of it unfit for pocket gophers, and they remain only in isolated areas where suitable environments still persist. _Specimens examined._--Total, 18, distributed as follows: _Millard County_: Desert Range Experiment Station, United States Forest Service, Sec. 9, T. 25 S, R. 17 W, Salt Lake Base Meridian, 6. _Beaver County_: Wah Wah Springs, Wah Wah Mountains, 30 mi. W Milford, 6,500 ft., 12 (2, M. V. Z.). =Thomomys bottae dissimilis= Goldman _Thomomys perpallidus dissimilis_ Goldman, Journ. Washington Acad. Sci., 21:425, October 19, 1931. _Thomomys bottae dissimilis_ Goldman, Proc. Biol. Soc. Washington, 48:156, October 31, 1935. _Thomomys perpallidus aureus_ Bailey, N. Amer. Fauna 39:75, November 15, 1915; Barnes, Bull. Univ. Utah, 12 (No. 15):85, April, 1922; Bull. Univ. Utah, 17 (No. 12):100, June, 1927. _Type._--Female, adult, skin and skull, No. 158526, U. S. National Museum (Biological Surveys Collection); E slope Mount Ellen, Henry Mountains, 8,000 ft., Garfield County, Utah; October 15, 1908; collected by W. H. Osgood; original number 3677 (after Goldman, type not seen). _Range._--Known only from the type locality.