Bill short, compressed; upper mandible with the dorsal line sloping to beyond the cere, then decurved, the sides sloping, the edge with a festoon a little anterior to the nostril, the tip acute; lower mandible with the dorsal line ascending and convex, the tip rounded. Nostrils large, ovato-oblong, with an oblique ridge from their upper edge. Head of moderate size, oblong, neck rather short; body slender. Legs long and slender; tarsi long, compressed, anteriorly and posteriorly scutellate; toes slender, scutellate unless at the base; claws long, compressed, moderately curved, flat beneath, acuminate. Plumage very soft; a distinct ruff of narrow feathers from behind the eye on each side to the chin, the aperture of the ear being very large. Wings long, much rounded, the fourth quill longest; outer four quills with their inner webs sinuate. Tail straight, long, slightly rounded. Quills and tail-feathers covered with velvety down. 26. 1. Circus cyaneus, Linn. Common Harrier. Plate CCCLVI. Fig. 1. Male. Fig. 2. Female. Fig. 3. Young. Adult male light ash-grey; abdomen, tail-coverts, lower wing-coverts, inner webs of secondary quills and tail-feathers, white, primaries black toward the end. Female umber-brown above, head, hind neck and scapulars, streaked with light red; tail-coverts white; tail banded with light red; lower parts light yellowish-red, the neck streaked with brown. Young like the female, but lighter. _Male_, 19-3/4, 44. _Female_, 20-1/2, 46-3/4. Breeds from Texas northward. Columbia River. Marsh Hawk, Falco uliginosus, Wils. Amer. Orn. v. vi. p. 67. Young Female. Falco cyaneus, Bonap. Amer. Orn. v. ii. p. 30. Hen-Harrier or Marsh Hawk, Nutt. Man. v. ii. p. 109. Marsh Hawk, Falco cyaneus, Aud. Orn. Biog. v. iv. p. 396. Buteo (Circus) cyaneus? var? Americanus, American Hen-Harrier, Swains. & Rich. F. Bor. Amer. v. ii. p. 55. FAMILY III. STRIGINÆ. OWLS.