For comparisons of absonus with Thomomys bottae aureus see account under that form.
Among named races of Thomomys bottae, absonus most closely resembles planirostris, but can be distinguished from the topotypes as follows: Size markedly smaller. Color: Lighter, more buffy throughout. Skull: Smaller, less ridged and more nearly flat; nasals convex as opposed to flat; extension of premaxillae posterior to nasals less; width of ascending processes of premaxillae less; zygomatic arches weaker; palate narrower; alveolar length of upper molar series shorter; tympanic bullae more inflated ventrally; molariform teeth smaller and lighter.
Remarks.—One specimen from Kanab is an intergrade between trumbullensis and absonus. The majority of its characters are with absonus to which it is referred (see Hall and Davis, 1934:52). Two specimens from Escalante are intergrades between absonus and dissimilis, but are referable to absonus.
Specimens examined.—Total, 3, distributed as follows: Garfield County: Escalante, 5,258 ft., 2 (B. Y. U.), Kane County: Kanab, 4,925 ft., 1 (M. V. Z.).
Thomomys bottae alexandrae Goldman
Thomomys alexandrae Goldman, Journ. Washington Acad. Sci., 23:464, October 15, 1933.
Thomomys bottae alexandrae Benson, Univ. California Publ. Zoöl., 40:449, December 31, 1935.
Type.—Male, adult, skin and skull, No. 250969, U. S. National Museum (Biological Surveys Collection); 5 mi. SE Rainbow Lodge, near Navajo Mountain, Coconino County, Arizona; June 16, 1933; collected by E. A. Goldman; original number 23613 (after Goldman, type not seen).
Range.—In extreme southwestern San Juan County, Utah. Known only from Navajo Mountain, probably limited to the area enclosed on the north by the Colorado and San Juan rivers, on the east and west by Navajo and Piute canyons, respectively.
Diagnosis.—Size small (see measurements). Color: Upper parts Cinnamon Buff, grading over the sides to Pinkish Buff on underparts; nose and top of head grayish black; hind feet and tail white; postauricular patches large and dark. Skull: Small and not heavily ridged; zygomatic arches widely spreading but weak; zygomatic arches nearly parallel; tympanic bullae moderately inflated ventrally; palate not arched; interpterygoid space U-shaped; dentition light.