Adult Male. Plate CLXXXVII. Fig. 1.
Bill long, straight, strong, tapering, compressed from the base; upper mandible encroaching a little on the forehead, slightly declinate at the tip, its dorsal line almost straight, the sides convex, the edges sharp and slightly inflected; lower mandible straight in its dorsal outline, convex on the sides, the edges sharp and involute, the tip acute and very slightly deflected, the gap-line slightly deflected at the base, and reaching to beneath the eye. Nostrils basal oval, half closed by a membrane. Head of moderate size, flattened, neck of moderate length, body rather slender, the whole form elegant. Feet of moderate length; tarsus compressed, anteriorly covered with seven scutella, sharp behind; toes rather long, scutellate above, the hind toe stronger, the lateral toes nearly equal, the middle one much longer; claws rather long, slightly arched, compressed, acute.
Plumage soft, blended, silky, highly glossed. Wings of ordinary length; third quill longest, second scarcely shorter, first and fourth about equal; the second, third, fourth, and fifth, cut out on the outer web towards the end; secondaries abruptly rounded with an acumen. Tail very long, graduated, broadly rounded at the end, of twelve rounded feathers, of which the two middle have their webs slightly bent upwards, the shafts and webs of all transversely undulated.
Bill, feet, and claws, black. Iris pale yellow. The general appearance of the plumage is black; but the head and upper parts of the neck all round are splendent deep bluish-purple, the back and breast anteriorly steel-blue, posteriorly bluish-green; the rump and tail-coverts darker. The abdomen, and lower tail-coverts and tibial feathers, plain black. Quills and tail black, slightly glossed with green on the outer webs.
Length 15⅞, extent of wings 23¾; bill along the ridge 1 5⁄12, along the edge 1¾; tarsus 1 10⁄12; tail-feathers 8½; weight 7½ ounces.
Adult Female. Plate CLXXXVII. Fig. 2.
The female is smaller. Her plumage is soft and blended, but is not glossed beneath, and on the upper parts is so only in a comparatively slight degree. The tail is graduated as in the male, but much shorter. The general colour of the upper parts is dusky, with slight tints of green and blue; the head and neck dull brown, with a paler band over the eye; the lower parts light reddish-brown, the tibial feathers and lower tail-coverts dusky.
Length 12⅝ inches, extent of wings 18; bill along the ridge 1 2⁄12, along the edge 1⅜; tarsus 1 7⁄12; tail-feathers 4¾; weight 3¾ ounces.
Individuals of both sexes, but especially males, differ greatly in size, from the time they obtain their full plumage until they are several years old, the difference sometimes amounting to several inches in the length of the birds, and affording an excellent opportunity of manufacturing new species.