Specimens examined.—One (U. S. N. M.) from E slope Mount Ellen, Henry Mountains, 8,000 ft., Garfield County.
Thomomys bottae aureus Allen
Thomomys aureus Allen, Bull. Amer. Mus. Nat. Hist., 5:49, April 28, 1893.
Thomomys bottae aureus Goldman, Proc. Biol. Soc. Washington, 48:156, October 31, 1935; Benson, Univ. California Publ. Zoöl., 40:450, December 31, 1935.
Thomomys fulvus aureus Goldman, Journ. Washington Acad. Sci., 21:417, October 19, 1931; Journ. Washington Acad. Sci., 23:464, October 15, 1933.
Thomomys perpallidus aureus Bailey, N. Amer. Fauna, 39:74, November 15, 1915; Barnes, Bull. Univ. Utah, 12 (No. 15):85, April, 1922; Bull. Univ. Utah, 17 (No. 12):100, June, 1927.
Type.—No. 5243/4123. American Museum of Natural History; Bluff City, San Juan County, Utah; May 12, 1892; collected by Charles P. Rowley (after Allen, type not seen).
Range.—All of San Juan County (except extreme southwestern part) and Grand County east of the Colorado River.
Diagnosis.—Size large (see measurements). Color: Upper parts Cinnamon Buff, lighter on sides; underparts generally white, or if colored at all with only a faint wash of Light Buff; nose and chin blackish gray; top of head blackish due to admixture of black hairs; postauricular patches small and dusky; front feet and hind feet white. Skull: Long, narrow but massive; zygomatic arches not widely spreading, but heavy; jugals thick, union of jugals and zygomatic processes of maxillae thickened; rostrum long but wide; top of rostrum convex in lateral view; ascending processes of premaxillae wide and heavy; nasals thin proximally; braincase long and narrow; tympanic bullae well inflated ventrally; alveolar length of upper molar series long; molars large; pterygoid hamulae heavy; interpterygoid space U-shaped; palate arched; upper incisors long and wide.