Type.—Male, no. 263890, U. S. Nat. Mus. Biol. Surv. Coll.; Dolphin Island, Great Salt Lake, 4250 ft., Box Elder County, Utah; obtained on June 4, 1938, by William H. [Marshall], original no. 57.
Range.—Dolphin Island, Great Salt Lake, Utah.
Diagnosis.—Size medium (see measurements). Color pale, upper parts near Pale Pinkish Buff, but lightly washed with black, purest on sides and flanks; arietiform markings, pinnae of ears, plantar surfaces of hind feet, dorsal and ventral stripes of tail, brownish. Skull medium in size; rostrum short; nasals relatively short; interparietal region relatively wide; auditory bullae but slightly inflated.
Comparisons.—From Dipodomys ordii utahensis, D. o. cineraceus differs in: Size smaller; color lighter; nasals longer; auditory bullae larger; total length of skull greater.
From Dipodomys ordii marshalli, D. o. cineraceus differs in: Size smaller; color darker; skull larger in all measurements taken.
Remarks.—The race D. o. cineraceus along with Dipodomys microps russeolus is found on Dolphin Island, Great Salt Lake, Utah. Dolphin Island is connected with the mainland by a bar that could allow animals from the island to disperse onto the mainland. There are no animals from the mainland, however, that are referable to D. o. cineraceus or to D. m. russeolus. The animals available from the mainland, at Kelton, although geographically near Dolphin Island, are referable to D. o. marshalli and to D. m. bonnevillei. The paucity of material from the mainland, adjacent to Dolphin Island, may be significant. Future trapping in this area is needed before we can be certain that D. o. cineraceus is isolated.
Specimens examined.—Total, 2, both from Utah, as follows: Box Elder County: Dolphin Island, Great Salt Lake, 4250 ft., 2 (USNM).
Dipodomys ordii marshalli [Goldman]
Dipodomys ordii marshalli [Goldman], Proc. Biol. Soc. Washington, 50:223, December 28, 1937.