Type.—None. Type locality California.
Racial characters.—Size large, total length of adults approximately 30 inches; tail long (nearly one-third of total length), thick, heavy and spiny; body stout; legs short; claws long and curved; ears and eyes small; body spines short, thick and most abundant on posterior part of back, longer and more slender on sides and shoulders; guard hairs of shoulders and sides long, almost concealing spines; fur of underparts shorter; color variable, brown, black or yellow. In winter the fur is longer and woolly, concealing spines.
Distribution.—The Columbian Plateau and the Blue Mountains.
Remarks.—[Anderson] and [Rand] (1943A: 295) ascribe two races to Washington. With inadequate material myself to verify this ascription. I think it probable that the northern forest porcupine and the Great Basin animal are racially different. In consequence the available names, nigrescens and epixanthum, are here applied, pending a revision of the entire genus.
Erethizon dorsatum nigrescens [Allen]
Erethizon epixanthus nigrescens [Allen], Bull. Amer. Mus. Nat. Hist., 19:558, October 10, 1903.
Erethizon epixanthum nigrescens [Miller], U. S. Nat. Mus. Bull., 128:437, April 29, 1924.
Erethizon dorsatum nigrescens [Anderson] and [Rand], Canadian Jour. Research, 21:293, September 24, 1943.
Type.—Obtained on the Shesley River, British Columbia, by M. P. [Anderson] on August 23, 1902; type in American Museum of Natural History.
Measurements.—A female from Sherman Creek Pass, Ferry County, measured: total length 770; length of tail 250; hind foot 95; ear 37. A female from Tye, King County, measured: 930; 280; 125; weight 20 pounds.