The colour of the head and neck of this species is black, very richly glossed with blue, which appears, in different directions of the light, highly splendid upon its surface. Upon the crown of the head the blue verges into violet and purple, and in descending towards the neck becomes changeable into a fine green, glossed with gold; these brilliant hues appear also on the sides of the neck, and passing round as a kind of pectorial band forms in particular a rich zone of golden green upon the breast. The pale ashen hue of the bill is singularly contrasted with the deep black and violet of the head and neck, and the sudden transition of the colours of the body is no less remarkable, the plumage in this part becoming abruptly of a fine yellow from the breast down to the thighs; these latter are black, but the vent feathers beyond are of a fine yellow, like the colour of the abdomen. The upper parts of the body are green glossed with yellowish and partaking of a golden lustre. The upper wing coverts and scapulars are dark fuscous, mottled with greyish; the quill feathers dark brown, quills from the base to the middle white. The tail is cuneated or wedge-formed, the middle feathers being longer than the outer ones. These feathers are most singularly contrasted with the rest, being of a fine dark green, glossed with gold, and at the tip black, while the three outer feathers on the contrary are white, and from the base downwards nearly to the tip very elegantly marked with oblique indented bars of black, leaving the tip of each feather immaculate; the inner one of these three exterior feathers are the same length as the dark ones, but the next outer feather is shorter, and the extreme exterior feather on each side shorter than the latter. There is a variety of this bird in which the belly, instead of being yellow, is white; the whole bird is a trifle smaller than the example now before us, and may possibly prove hereafter to be the same species, in a less mature state of plumage. Buffon calls it _Le Couroucou verd_. All the birds of this tribe at present known are inhabitants of the warmer climates of South America and India. Our present subject is a native of Cayenne, where it lives in damp and retired woods, building upon the lower branches of trees and feeding chiefly upon insects, with which the trees and herbage in those countries abound. This truly interesting and very beautiful species is already known in our language by the epithet of the yellow-bellied Trogon or Curucui. There is, however, another bird of the same genus, which has the belly yellow, as in the present bird; we allude to the Rufous Curucui, the better therefore to define our species we have denominated it the yellow-bellied Green Trogon, or Curucui, as the least attention to the difference in the general colour of the plumage will thus enable the most cursory observer to discriminate the two species with facility and accuracy.