They give the part of the tongue on which they occur the appearance and feel of a coarse rasp. The feet are furnished with round soft pads or cushions covered with thick, naked skin, one on the under surface of each of the principal toes, and one larger one of trilobed form, behind these, under the lower ends of the metacarpal and metatarsal bones, which are placed nearly vertically in ordinary progression.
There is no trace of a first toe, and the fifth metatarsal is represented by a small nodule.
In the absence of any trace of the lower extremities of the metacarpal and metatarsal bones of the lateral toes the skeleton differs from the American deer, and resembles those hollow-horned ruminants in which these toes persist.
Reduction and final loss of outer pair of digits (second and fifth), with coalescence of the metacarpal and metatarsal bones of the two middle digits to form a cannon-bone.
White-tailed Group, Subgenus Dorcelaphus or Odocoileus.- Antlers large and complex, with a sub-basal snag, and the lower prong more or less developed at the expense of the upper one; metatarsal gland usually present; tail long or moderate, and hairy below; face very long and narrow; the face-gland small, and the gland-pit in the skull of moderate extent; no upper canines; size generally large.
Hind-feet with no trace of first toe externally, but the metatarsal bone is present.
The most interesting genera are, however, the Upper Oligocene and Lower Miocene Gelocus and Prodremotherium, which have perfectly selenodont teeth, and the third and fourth metacarpal and metatarsal bones respectively fused into an imperfect cannon-bone, with the reduction of the lateral metacarpals and metatarsals to mere remnants of their upper and lower extremities.
Hind extremities proportionally longer with inner toe represented only by a small metatarsal bone.
The primitive Artiodactyla thus probably had the typical number (44) of incisor, canine and molar teeth, brachyodont molars, conical odontoid process, four distinct toes on each foot, with metacarpal, metatarsal and all the tarsal bones distinct, and no frontal appendages.
The metapodals and phalanges resemble very closely those of the fore limb, but the principal metatarsal is more laterally compressed at its upper end than is the corresponding metacarpal.