Large, adult, entire plumage above, dark-brown, every feather mottled, and with irregular lines of ashy-white and reddish fulvous, the latter being the color of all the plumage at the bases of the feathers. Ear-tufts, dark-brown, nearly black, edged on their inner webs with dark fulvous, a black spot above and extending somewhat in front of the eye, radiating feathers behind the eye, dark reddish fulvous, feathers of the facial disc tipped with black; throat and neck before, white; breast, with wide longitudinal stripes of black; other under parts finely variegated with white and fulvous, and every feather having transverse narrow lines of dark-brown. In many specimens, the middle of the abdomen is pure white; legs and toes light fulvous, generally unspotted, but in some specimens, with transverse narrow bars of dark-brown; quills, brown, with wide transverse bands of cinereous, tinged on the inner webs with pale fulvous; tail, the same, with the pale fulvous predominating in the outer feathers; iris, yellow; bill and claws, dark. The colors of the plumage, and the size also, in this species, vary materially. There may be distinguished the following varieties, which appear to be permanent in individual specimens, and are to some extent geographical. Though at present, with a large number of specimens before us, we are of opinion that they are all of one species, it may be that they are distinct: Variety, _atlanticus_. The common species as just described. Feathers of the face behind the eye, always bright reddish fulvous, and the entire plumage more marked with that color than in the others, as below. This variety inhabits the eastern and northern portion of North America. Variety, _pacificus_. Feathers of the face, behind the eye, ashy, generally faintly tinged with fulvous. General plumage with the fulvous color paler than the preceding. This variety appears to be restricted to the west, and nearly all the specimens that we have seen are of a smaller size than it is usual to find in the eastern bird, though we have seen specimens of the latter which were not larger. Variety, _arcticus_. Bubo arcticus. Swainson, Faun. Bor. Am. Birds, p. 86, pl. 30. (1831.) Bubo sub-arcticus. Hoy, Proc. Acad., Philada., VI. p. 211. (Dec. 1852.)? Bubo septentrionalis. Brohm., Vog. Deutschl., p. 120. (1831.)? Strix scandiaca. Linn., Syst. Nat., I. p. 132. (1766.)?