Xanthoura, Bonaparte, Consp. Av. 1850. (Type, “Corvus peruvianus, Gm.”)
Char. Head without crest. Throat black. Lateral tail-feathers bright yellow. Bill very stout, rather higher than broad; culmen curved from the base. Nostrils rather small, oval, concealed by a nasal tuft varying in length with species. Tail longer than the wings; graduated. The wings concave, rounded; the secondaries nearly as long as the primaries. Legs very stout; hind claw about half the total length of the toe.
Xanthoura luxuosa.
4052
The genus Xanthoura is composed of three so-called species, of different geographical distribution, and exhibits a progressive change from one to the other, with variation of latitude that enforces assent to the hypothesis
of their all belonging to one primitive form. These differences may be expressed as follows:—
Common Characters. Nasal tufts, patch on side of lower jaw and one above eye, (both eyelids,) bright blue; remainder of face and throat black. Back, and upper surface of wings and tail (the four central feathers), green, the latter tinged with blue at end; the rest of tail-feathers bright yellow. Belly and crissum varying from bright yellow to green. Forehead yellowish or whitish.
a. Nasal tufts short, only covering the nostrils; whole top of head (except anteriorly) and nape bright blue.
1. Body beneath, and crissum, green. Hab. Mexico and South Texas … var. luxuosa.
2. Body beneath, and crissum, yellow, sides more greenish. Hab. Guatemala and Honduras … var. guatemalensis.