Type.—Male, no. 4611, Mus. Zool., Univ. Utah; at approximately 4,000 ft. on sandy soil, immediately north of the northern of two large cinder cones in Diamond Valley, 10 mi. N St. George, Washington County, Utah; obtained on February 13, 1944, by Ross Hardy, original no. 2690.
Range.—Diamond Valley, Washington County, Utah, north through Mountain Meadows, east as far as Cedar City, Iron County, Utah, north through the Escalante Desert to Lund, Iron County, and west almost to the Utah-Nevada boundary; marginal occurrences, all in Utah are: 11 mi. SE Lund; N end Mountain Meadows; Diamond Valley; 10 mi. W Cedar City; 4-1/2 mi. NW Summit and 6 mi. W Parowan.
Diagnosis.—Size small (see measurements). Color dark, upper parts near Buffy Brown, strongly suffused with black, purest on sides and flanks; pinnae of ears, plantar surfaces of hind feet, dorsal and ventral stripes of tail, arietiform markings, black. Skull small; rostrum narrow; auditory bullae relatively as well as actually well inflated; external auditory meatus small; interparietal region narrow.
Comparisons.—From Dipodomys ordii fetosus, D. o. cinderensis differs in: Size smaller; color darker; skull smaller in all measurements taken.
From Dipodomys ordii panguitchensis, D. o. cinderensis differs as follows: Size smaller; color lighter; skull smaller except for auditory bullae which are larger; external auditory meatus smaller; maxillary tooth-row longer.
Compared with Dipodomys ordii longipes and Dipodomys ordii cupidineus, D. o. cinderensis is smaller, darker and can easily be distinguished.
For comparisons with Dipodomys ordii celeripes and Dipodomys ordii utahensis see accounts of those subspecies.
Remarks.—This race confined to Utah, and inhabiting northern Washington County and most of Iron County, is restricted almost exclusively to areas of loose shifting sand. Intergradation with Dipodomys ordii fetosus occurs near Lund. The animals from this locality intergrade in size of body and in color, but in the majority of cranial characters resemble D. o. cinderensis. In all characters studied D. o. cinderensis appears to be more closely related to Dipodomys ordii utahensis than to any other subspecies with which it comes into actual contact.
Animals from near Parowan have both cranial and external characters by which they could be referred to either D. o. panguitchensis or D. o. cinderensis. Owing to the existence of the physical barrier (Cedar Mountains) separating the two populations, they are referred to D. o. cinderensis. Dipodomys ordii cinderensis is not a well differentiated race but appears to possess characters sufficiently diagnostic to distinguish it from contiguous forms.