The large ears, brownand-white face, short, black-tipped tail, and antlers without large basal snag serve to distinguish the mule-deer M.
Thus a fall in the gradient at any point in the course of a stream; any snag, projection or dam, impeding the current; the reduced velocity caused by the overflowing of streams in flood and the dissipation of their energy where they enter a lake or the sea, are all contributing causes to alluviation, or the deposition of streamborne sediment.
The antlers are large and curve forwards, giving off an upright snag near the base, and several vertical tines from the upper surface of the horizontal portion.
- Lateral metacarpals as in Rangifer; antlers very variable in size, forming a marked angle with the plane of the face, without a brow-tine; when consisting of more than a simple prong, dichotomously forked, frequently with a subbasal snag, and always with the lower prong of the fork projected from the front edge of the beam, in @ome cases the lower, in others the upper, and in others both prongs again dividing; tail long; tarsal gland generally present; metatarsal gland very variable, both as regards presence and position; vomer dividing the inner aperture of the nostrils in the skull into two distinct chambers.
- Antlers large and complex, without a sub-basal snag, and the upper prong more developed than the lower one; metatarsal gland absent; tail short; face moderately long; face-gland and gland-pit well developed; upper canines usually present in male.