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. Inhabits Java and other parts of India, and is I believe unfigured. The line at the bottom of the plate is on the scale of an inch. Since writing the above, Temminck's new edition of the _Manuel d'Ornithologie_ has just reached me, in which I perceive he has continued the birds of this genus under that of _Alcedo_, observing that their plumage is always shining, and that he can find no characters for their geographic distribution: yet, notwithstanding the opinion of this eminent ornithologist, a close attention will I believe prove, first, that no species of Linnaean _Alcedo_ bearing the characters of _Halcyon_ have yet been discovered as natives of America; and secondly, that species of genuine _Alcedo_ will be found with plumage quite devoid of any bright or shining colours. One or two exist in my own cabinet, but to which I cannot now refer. The situation of _Halcyon_ will be between _Alcedo_ and _Dacelo_; from the last of which it is distinguished by its perfectly straight, acute, and entire upper mandible, which, on the contrary, in _Dacelo_ is notched, the tip bent and obtuse. * * * * * Pl. 28 [Illustration] HESPERIA Haworthiana. _Haworth's Hesperia._ * * * * * GENERIC CHARACTER. _Antennae mediocres vel elongatae, rectae, graciles; clava subterminali, brevi, crassata, cylindracea; unco abrupto, brevi, acuminato. Palpi in fronte compressi, incurvati, lateribus convexis vel angulatis, articulo ultimo erecto, verticali. Alae (sedentes) erectae._ DIVISIONES. I. _Palpi lati, in fronte compressissimi. Antennae breves, clava crassissima._ II. _Palpi pene quadrati, crassissimi. Antennae elongatae._ III. _Palpi articulo ultimo longiore, gracile. Antennae mediocres._ Typus Genericus _Hesperia Comma_ Auctorum.