Dipodops ordii, Merriam, N. Amer. Fauna, 4:42, October, 1890 (part—the part from El Paso, Texas).
Cricetodipus ordii, Trouessart, Catalogus Mammalium, 1:581, 1897.
Perodipus ordi, Elliot, Field Columbian Museum, Zool. Ser., 2:238, 1901.
Perodipus montanus richardsoni, [Bailey], N. Amer. Fauna, 25:144, October, 1905 (part—the part from Carlsbad, New Mexico).
Perodipus ordii, [Goldman], Proc. Biol. Soc. Washington, 30:113, May 23, 1917.
Type.—None designated. Species characterized from specimens obtained by Dr. Woodhouse at El Paso, Texas.
Range.—Southeastern Arizona, southern New Mexico, western Texas and north-central Mexico; marginal occurrences are: in Arizona, 20 mi. NE Calva, Oracle and Calabasas; in Sonora, Nogales; in Chihuahua, Casas Grandes, Corralitos and Santa Rosalia; in Texas, 16 mi. E Van Horn and 30 mi. N Van Horn; in New Mexico, 40 mi. N Roswell, 40 mi. SE Corona and Mangos Valley.
Diagnosis.—Size small (see measurements). Color dark, entire dorsal surface (16") between Pinkish Cinnamon and Cinnamon-Buff, purest on sides and flanks, upper parts suffused with black; arietiform markings, pinnae of ears, plantar surfaces of hind feet, dorsal and ventral stripes of tail, brownish-black. Skull of medium size; rostrum narrow and relatively long; braincase flattened; auditory bullae but slightly inflated; zygomatic arches slender and straight; upper incisors short and narrow.
Comparisons.—From Dipodomys ordii richardsoni, D. o. ordii differs as follows: Size smaller; color somewhat lighter; dorsal and ventral stripes of tail brownish instead of blackish; skull smaller in all measurements taken.