Type.—Male, adult, no. 55115, U. S. Nat. Mus. Biol. Surv. Coll.; Ogden, Weber County, Utah; obtained on July 15, 1893, by Vernon [Bailey], original no. 4085.
Range.—Between Great Salt Lake and the Wasatch Mountains from extreme northern Utah, south to northern Sevier County, Utah; marginal occurrences, all in Utah, are: Promontory Point, Ogden, St. John, Cedar Valley, Nephi, Aurora, Spring City, Provo and 4 mi. N Draper.
Diagnosis.—Size small (see measurements). Color dark, entire dorsal surface (a) between Cinnamon-Buff and Clay Color, purest on sides, flanks and cheeks, with heavy admixture of black in upper parts; arietiform markings, pinnae of ears, plantar surfaces of hind feet, dorsal and ventral stripes of tail blackish. Skull small; rostrum short and narrow; interorbital region moderately wide; interparietal large, spatulate anteriorly; lacrimal processes relatively large; braincase vaulted; zygomatic arches robust and straight; auditory bullae relatively, as well as actually, greatly inflated.
Comparisons.—From Dipodomys ordii marshalli, D. o. utahensis differs as follows: Size smaller; color darker; skull smaller; rostrum longer and narrower; interorbital region wider; lacrimal processes larger; interparietal region larger; auditory bullae less inflated; palate longer and narrower.
From Dipodomys ordii pallidus, D. o. utahensis differs in: Size smaller; color darker; skull smaller; rostrum shorter and narrower; interorbital region narrower; auditory bullae less inflated laterally, posteriorly and ventrally; interparietal region larger; lacrimal processes smaller; foramen magnum with ventral notch as opposed to rounded ventrally; pterygoid fossae circular as opposed to subcircular; palate longer and narrower.
From Dipodomys ordii cinderensis, D. o. utahensis differs as follows: Size larger, except hind foot which is shorter; color somewhat lighter, more reddish; skull larger; rostrum longer; nasals longer; braincase more vaulted; pterygoid fossae circular as opposed to subcircular; auditory bullae less inflated laterally but more inflated ventrally.
For comparisons with Dipodomys ordii columbianus, D. o. fetosus, D. o. marshalli, D. o. panguitchensis and D. o. cineraceus see accounts of those subspecies.
Remarks.—The systematic status of D. o. utahensis has long been in doubt. Several workers have, at various times, considered it to be indistinguishable from Dipodomys ordii columbianus. [Durrant and Setzer] (1945:29) recognized it as a valid subspecies and gave diagnostic characters by which it could be distinguished from D. o. columbianus.
Intergradation has been noted in specimens from the eastern and southeastern shores of Great Salt Lake. In color and the width of the auditory bullae these specimens are intermediate between D. o. utahensis and Dipodomys ordii marshalli but in the sum total of characters are referable to the latter. Specimens from 20 miles southwest of Nephi and from U. B. (Yuba) Dam are darker and intermediate in rostral width and breadth of the auditory bullae but are referable to Dipodomys ordii celeripes.