Bill of moderate length, straight, tapering, compressed from the base; upper mandible prolonged on the forehead, forming an acute angle there, a little declinate at the tip, the dorsal outline slightly convex, the sides convex, the edges sharp and inflected; lower mandible nearly straight in its dorsal outline, convex on the sides, the edges sharp and inflected; gap-line deflected at the base. Nostrils basal, oval, half closed above by a membrane. Head of ordinary size, neck rather short, body rather slender. Feet of moderate length, strong; tarsus compressed, with a few long scutella anteriorly, sharp behind; toes compressed, the lateral nearly equal, the outer united as far as the second joint to the middle, which is much longer, hind-toe not much stouter than the inner; claws rather long, arched, compressed, very acute.
Plumage soft, blended, glossy. Wings rather long, second quill longest, first and fourth equal. Tail rather long, slightly rounded, of twelve broad feathers.
Bill and feet black. Iris pale yellow. The general colour is deep black, with greenish and bluish reflections.
Length 9¼ inches, extent of wings 14¼; bill along the back ¾, along the edge 11⁄12; tarsus 1¼.
Adult Female. Plate CLVII. Fig. 2.
Bill, iris, and feet as in the male. The general colour is brownish-black; the sides of the head over the eyes, and a broad band beneath it light yellowish-brown, the feathers of the lower parts more or less margined with brownish.
Length 8 11⁄12 inches, extent of wings 13½.
Young bird fully fledged. Plate CLVII. Fig. 3, 3.
Bill and feet brownish-black. Iris pale yellow. Head and neck light brown, the rest of the upper parts brownish-black, edged with light reddish-brown, the rump tinged with grey. A band over the eye, and the fore part and sides of the neck and breast pale yellowish-brown, sides tinged with brown, under tail-coverts dusky.