"_Skull._--Similar in general to that of _T. b. aureus_, but braincase conspicuously broader and flatter; zygomata more widely spreading; nasals shorter; premaxillae more attenuate posteriorly; interparietal larger; audital bullae more rounded and fully inflated anteriorly; incisors short, as in _aureus_, but less strongly recurved. Compared with that of _T. b. osgoodi_ the skull is much larger, with flatter braincase, shorter nasals, and posteriorly narrower premaxillae." _Remarks._--Six specimens, in the Carnegie Museum from 10 miles north of Moab, Grand County, Utah, were available for this study. They are not typical of _howelli_ as it is diagnosed by Goldman (_loc. cit._). They appear to be intergrades between _howelli_ and _osgoodi_ in cranial characters, but more closely resemble _howelli_, particularly in the flat, widened, low braincase. In color, some specimens seem to intergrade toward _aureus_. The range ascribed to this form in Utah appears to be one of the most natural ones within the state since it is bounded by the Green and Colorado rivers which have formed deep rocky gorges in this region. _Specimens examined._--Total, 6, as follows: _Grand County_: 10 mi. N Moab, 6 (C. M.). =Thomomys bottae wahwahensis= Durrant _Thomomys bottae wahwahensis_ Durrant, Bull. Univ. Utah, 28 (No. 4):4, August 18, 1937. _Type._--Male, adult, skin and skull, No. 1750, Museum of Zooelogy, University of Utah, Wah Wah Springs, 30 mi. W Milford, 6,500 ft., Beaver County, Utah; July 22, 1936; collected by S. D. Durrant; original number 989. _Range._--Westcentral Utah, in Wah Wah Mountains, and Pine Valley to the west of these mountains. _Diagnosis._--Size medium (see measurements). Color: Upper parts Pinkish Buff; underparts Pale Pinkish Buff with considerable admixture of gray; inguinal and pectoral regions Pale Pinkish Buff; nose and cheeks grayish black; postauricular patches small and black; front feet, hind feet and distal one-third to one-half of tail white. Skull: Flat dorsoventrally; rostrum short and wide; premaxillae broad and heavy; nasals short and straight, with no arching as viewed laterally; tympanic bullae small; space enclosed within zygomatic arches short antero-posteriorly; alveolar length of upper molar series short; molariform teeth small. _Comparisons._--From topotypes of _Thomomys bottae centralis_, _wahwahensis_ differs as follows: Size smaller in every measurement taken. Color: Lighter, Pinkish Buff as opposed to Cinnamon Buff. Skull: Rostrum wider, shorter and more nearly flat; nasals straight as opposed to moderately convex; tympanic bullae smaller and less inflated ventrally; zygomatic arches more widely spreading and angular; molariform teeth smaller; extension of premaxillae posterior to nasals less.