A. Otus, Cuvier. Ear-tufts well developed; outer quill only with inner web emarginated.
Colors blackish-brown and buffy-ochraceous,—the former predominating above, where mottled with whitish; the latter prevailing beneath, and variegated with stripes or bars of dusky. Tail, primaries, and secondaries, transversely barred (obsoletely in O. stygius).
1. O. vulgaris. Ends of primaries normal, broad; toes feathered; face ochraceous.
Dusky of the upper parts in form of longitudinal stripes, contrasting conspicuously with the paler ground-color. Beneath with ochraceous prevalent; the markings in form of longitudinal stripes, with scarcely any transverse bars. Hab. Europe and considerable part of the Old World … var. vulgaris.[19]
Dusky of the upper parts in form of confused mottling, not contrasting conspicuously with the paler ground-color. Beneath with the ochraceous overlaid by the whitish tips to the feathers; the markings in form of transverse bars, which are broader than the narrow medial streak. Wing, 11.50–12.00; tail, 6.00–6.20; culmen, .65; tarsus, 1.20–1.25; middle toe, 1.15. Wing-formula, 2, 3–4–1. Hab. North America … var. wilsonianus.
2. O. stygius.[20] Ends of primaries narrow, that of the first almost falcate; toes entirely naked; face dusky, or with dusky prevailing.
Above blackish-brown, thinly relieved by an irregular sparse spotting of yellowish-white. Beneath with the markings in form of longitudinal stripes, which throw off occasional transverse arms toward the edge of the feathers. Wing, 13.00; tail, 6.80; culmen, .90; tarsus, 1.55; middle toe, 1.50. Wing-formula, 2, 3–4, 1. Hab. South America.
B. Brachyotus, Gould (1837). Similar to Otus, but ear-tufts rudimentary, and the second quill as well as the first with the inner web emarginated.
Colors ochraceous, or white, and clear dark brown, without shadings or middle tints. Beneath with narrow longitudinal dark stripes upon the whitish or ochraceous ground-color; crown and neck longitudinally striped with dark brown and ochraceous.