_Description._--Bill straight, entirely black and as long as the head; whole upper part of the body of a dark green metallic colour, except the wings, which are black; the small feathers of the throat on the under jaw are whitish with a darker spot in the middle; there begins on the throat the crimson-red bilateral beard, which is composed on both sides of three rows of very small feathers, these becoming somewhat larger in the middle of the beard and terminating with two ranges of feathers in the exterior half part. Many of these feathers are shining metallic green in certain positions. A white spot behind the eyes descends from there to the breast, which is also whitish, but with a dark spot on every feather, causing a greyish appearance in the middle of the breast. The hinder half of the breast and the belly are black, but the anal portion is white, as also the sides of the body, except the thighs, which are black. The inferior feathers behind the anal region are clear yellow-brown, but those in the middle have a green metallic spot. The tail is composed of eight feathers; the two exterior on each side are more than an inch long, very small but of equal size in the whole extent, and rounded at the tip, not pointed. The exterior rectrix is entirely black; the second has a clear brown stripe on the inside border. The third feather of each side is very short, only half an inch long and more than eight lines shorter than the exterior; its colour is entirely black. The fourth feathers on each side, that is in the middle of the tail, are shorter than the third pair and partly covered by the coverts: they are of metallic green colour like the coverts. _Hab._ Tucuman. The only known specimen of this species was procured in the Valle de Tafi, in the mountains of Tucuman, by Herr Schulz, and is now in the National Museum of Buenos Ayres. This species is nearly allied to _C. bombus_, Gould (Mon. Troch. Suppl. p. 45, pl. 32), but differs in the form of the tail. The figure (Plate XI.) is taken from a watercolour sketch of this specimen kindly sent to us by Dr. Burmeister. 232. SPARGANURA SAPPHO (Lesson). (SAPPHO HUMMING-BIRD.) +Sparganura sappho+, _Scl. et Salv. Nomencl._ p. 86; _White, P. Z. S._ 1882, p. 615 (Catamarca). +Cometes sparganurus+, _Burm. La-Plata Reise_, ii. p. 449 (Mendoza, Catamarca, Tucuman); _Gould, Mon. Troch._ iii. pl. 174. +Sappho sparganura+, _Elliot, Syn. Troch._ p. 154; _Salvin, Ibis_, 1880, p. 360 (Tucuman, Salta).