Bill very wide at base, short; wings long; tail rather short, emarginate; forehead white, nearly pure in some specimens, but generally tinged with reddish chestnut; head above and back bluish-black, with a purple lustre; plumage of the back usually edged and streaked with grayish white; rump pale chestnut; throat dark brownish chestnut, which color extends upwards and forms a complete collar around the neck behind; lores and large spot on the neck in front black; entire other under-parts ashy-white, tinged with pale chestnut, especially on the breast; under tail coverts with a green lustre, and tipped with pure white; wings and tail brownish-black; bill and feet dark; sexes very nearly alike. Dimensions. Total length, 5½ inches; wing, 4⅜; tail, 2 inches. Female rather smaller. Hab. Throughout North America. Oregon (Dr. Townsend); California (Dr. Heermann); New Mexico (Col. McCall); Texas (Dr. Woodhouse); Indiana (Rufus Haymond, M. D.); Canada (Dr. Hall). This handsome species is now well known throughout almost the whole of the United States, but is said to have appeared for the first time in the States on the Atlantic seaboard within the memory of persons now living. It builds a curiously-formed nest of the shape of a gourd, faithfully represented in Mr. Audubon’s plates, cited above. _Hirundo fulva_, Vieill., is an allied species, but much smaller, and not ascertained to inhabit any part of North America. It is best known as a bird of the Island of Jamaica. The paper referred to above, in which this bird is named _Hirundo opifex_, possesses additional interest, from the fact that it was written by the late De Witt Clinton, formerly Governor of the State of New York, who had given particular attention to American Natural History. 3. Hirundo bicolor. Vieill., Ois. d’Am., Sept. 1, p. 61. (1807.) The White-bellied Swallow. Hirundo viridis. Wilson, Am. Orn. V. p. 44. (1812.) Hirundo leucogaster. Stephens, Gen. Zool. X. p. 106. (1817.) Vieill., Ois. d’Am., Sept. 1, pl. 31; Wilson, Am. Orn. V. pl. 38, fig. 3; Aud., Birds of Am., pl. 98, Oct. ed. I. pl. 46; Nat. Hist. N. Y. Birds, pl. 29, fig. 1. Wings long, exceeding the tail, pointed; tail deeply emarginate; entire upper parts uniform dark green, changing to blue in some lights, very glossy; wings and tail brownish-black, slightly tinged with green; entire under-parts silky-white, generally with a tinge of cinereous; bill black; feet yellow; sexes alike, but the female with the colors duller. Dimensions. Total length, male, 5½ inches; wing, 4¾; tail, 2¼ inches. Hab. Throughout North America. Canada (Dr. Hall); Oregon (Dr. Townsend); California, Texas (Dr. Woodhouse); Cuba (Mr. Lembeye); Wisconsin (Dr. Hoy); Northern Ohio (Prof. Kirtland); Long Island (Mr. Giraud).