Typus Genericus _Alcedo Senegalensis_. Linn.
Bill very long, straight, thick, the base broader than high; the sides tetragonal; upper mandible very straight, the base rounded; under mandible beneath carinated and recurved, the margins covered by those of the upper. Nostrils basal, covered by a membrane, the aperture naked, linear and oblique. Tail mostly moderate. Feet gressorial: interior fore-toe small or wanting.
Generic Type _Crabeating Kingsfisher_. Latham.
_H. viridi-cærulea; corpore subtus, lunulaque cerviculi albis._
Greenish-blue. Body beneath and nuchal collar white.
Alcedo collaris. _Latham Index Ornith._ i. 250.
Sacred Kingsfisher, _Var._ D. _Latham Syn._ ii. _p._ 623.
Collared Kingsfisher. _Gen. Zool._ viii. i. _p._ 80.
Referring to the observations we have already made on Kingsfishers generally, it will be only necessary to observe, that the species now formed into the genus _Halcyon_ appear entirely excluded from the American continent: their bills are much stronger, thicker, and more rounded than the genuine Kingsfishers, and the under mandible beneath invariably carinated and curving upwards. One of them (the _Alcedo Senegalensis_ of Latham) is known to feed on crabs, the breaking and disjointing of which this structure seems admirably calculated to accomplish; and although some authors mention insects also as their food, I apprehend it is only in the absence of other larger prey more suited to the construction of their bills.
Total length eight inches and a half. Bill two inches three lines from the gape, and one inch three quarters from the nostrils; upper mandible and margin and lip of the lower, black, the rest yellowish-white. The general plumage above is pale and changeable greenish-blue, the green predominating on the scapulars, head and tail; the upper part of the neck is crossed by a white collar, separated from the green of the head by a narrow margin of black, which passes on the ear-feathers round the nape; a narrow whitish line runs from the nostrils to the eyebrows, and another very short one is beneath the eye; the whole of the under plumage white. Quills black edged with blue, the second, third and fourth equal and longest. Wings four inches and a quarter. Tail even, near three inches long, above blue-green, beneath black. Feet dusky; middle and outer claws much longer than the leg.