This form constitutes so strongly marked a variety as to be worthy of particular description. The general appearance is that of _P. arcticus_, which it resembles in the amount of white spotting on the wings. This, however, does not usually involve the whole outer web at the end, but, as in _oregonus_, has a narrow border of black continued around the white terminally and sometimes externally. There is not quite so much of a terminal white blotch on the outer tail-feather, this being but little over an inch in length, and the outer web of the same feather is never entirely white, though always with an external white border, which sometimes is confluent with the terminal spot, but usually leaves a brown streak near the end never seen in _arcticus_, which also has the whole outer web white except at the base. From _oregonus_ the species differs in the much greater amount of white on the wings and the less rounded character of the spots. _Oregonus_, too, has the whole outer web of external tail-feather black, and the terminal white spot of the inner web less than an inch in length. We have never seen in _oregonus_ any concealed white spotting on the sides of the head. The greatest difference between this race and the two others lies in the stout tarsi and enormously large claws, as described, both the lateral extending greatly beyond the base of the middle one, the hinder toe and claw nearly as long as the tarsus. The only North American passerine birds having any approach to this length of claw are those of the genus _Passerella_. This great development of the claws is especially apparent in specimens from the Southern Sierra Nevada, the maximum being attained in the Fort Tejon examples; those from as far north as Carson City, Nev., however, are scarcely smaller. In most Rocky Mountain Pipilos, the claws are but little longer than in _arcticus_. In this race the female is not noticeably different from the male, being of a merely less intense black,—not brown,—and conspicuously different as in _arcticus_ and _oregonus_; there is, however, some variation among individuals in this respect, but none are ever so light as the average in the other races. The young bird is dusky-brown above, with a slight rusty tinge, and obsolete streaks of blackish. White markings as in adult, but tinged with rusty. Throat and breast rusty-white, broadly streaked with dusky; sides only tinged with rufous.