UROSTICTE RUFICRISSA, Lawrence. Red-vented White-tip. Urosticte ruficrissa, Lawrence, Annals of the Lyceum of Nat. Hist. New Bor epny Ieper (1864).—Sclater & Salv. Nomencl. Av. Neotr. p. 87 (1873).—Muls. Hist. Nat. Oiseaux-Mouches, iii. p. 103 (1876).—Elliot, Synopsis of the Humming-Birds, p. 90 (1878). Tur genus Urosticte was established by me in my introduction to the present Monograph for the reception of the single species at that time known, U. benjamini. The bill is much longer than the head, and straight, the tail being slightly forked, and the tarsi clothed. One special characteristic is the beautiful luminous throat ; while the sexes are different in colour; the female being much less brightly plumaged. Its nearest ally would appear to be the genus Heliangelus, which it resembles in form of Dill, this being straight as in the last-named genus, but more slender. Since finishing my Monograph a second species of Urosticte has been described by my friend Mr. G. N. Lawrence, who has bestowed on it the appropriate name of U. ruficrissa. It is nearly allied to U. benjamini, and, like that species, has the central tail-feathers bronzy and tipped with white ; it wants, however, the beautiful violet spot on the throat, which is so conspicuous in the above-named bird, having this part entirely ereen; and it is further distinguished by its rufous under tail-coverts. The home of the present bird, like that of its congener, is Ecuador. Mr. Elliot, in bis excellent ‘ Synopsis,’ bas given a very good diagnosis for the species, which I here reproduce :— “Male. General plumage dark shining green. Throat luminous grass-green. Wings purplish brown. Under tail-coverts rufous. Tail pale bronze-green, with the four median feathers tipped with white. Bill black, feet brown. Total Jength 4 inches, wing 2, tail 23, culmen 3.” «Female. Exactly like the female of U. benjamini, but slightly larger and with a Jonger bill.” The Plate represents two males and a female, drawn from the typical specimens lent to me by Mr. Lawrence.