Bill moderately wide at base, rather strong, curved; wings reaching about to the end of the tail, which is deeply emarginate; legs short; toes rather long. Male.—Entire plumage above and below deep black, with a purple and blue silky lustre; quills and tail less lustrous, and in many specimens plain brownish-black; bill and feet black. Female. Upper-parts same as in the male, but paler; under-parts ashy-brown, dark on the throat and breast; paler and sometimes nearly white on the abdomen; under tail coverts dark brown, every feather edged with ashy-white. Dimensions. Total length, male, 7½ inches; wing, 5¾; tail, 3 inches. Female slightly smaller. Hab. Eastern North America. Canada (Dr. Hall); Oregon (Dr. Townsend); Texas (Dr. Woodhouse); Cuba (Mr. Lembeye); Florida (Mr. John Lee Williams). In mature plumage, a beautiful species. This bird is common throughout the eastern United States, and comes with much punctuality in the spring to take possession of the boxes prepared for its accommodation in the rural districts, and occasionally in the cities. Our esteemed friend, Mr. Thomas Fisher, an eminent mathematician of this city, has been annually visited by a colony of this species for several years, though his residence is in one of the most dense parts of Philadelphia. This bird is nearly allied to several species of South America and the West Indies. In fact, the genus _Progne_ is one of the most difficult of the family of Swallows. 2. Progne chalybea. (Gmelin.) The Western Martin. Hirundo chalybea. Gm., Syst. Nat. I. p. 1026. (1788.) Buff, Pl. Enl. 545, fig. 2. Size smaller than that of the preceding; bill very wide at base, much longer than in the preceding, gradually compressed to the tip, curved; wings reaching about to the end of the tail, which is deeply emarginate; under tail coverts long; legs short. Male, adult? Plumage of the upper parts dusky black, with a dark green lustre; throat and breast ashy white, running into light smoky brown on the sides of the neck, breast, and flanks; abdomen and under tail-coverts pure white, many feathers having dark lines on their shafts; under wing-coverts and axillaries fuliginous brown. Female? Similar to the male, but less lustrous on the upper parts, and with the entire plumage more tinged with fuliginous; under tail-coverts pure white, many feathers with dark shafts; bill and feet dark. Dimensions. Total length, about 6¾ inches; wing, 5¼; tail, 3 inches. Female slightly smaller. Hab. Western North America. South America, California, Panama (Mr. Bell).