Chin white; all the rest of the plumage black.
C. murarius, Temm. Man. d'Orn. torn. I. p. 434. Id. torn. III. p. 303. Common Swift, Selb. Illust. vol. I. p. 127. pl. 42. f. 4. Swift, Mont. Orn. Diet. Bew. Brit. Birds, vol. I. p. 296.
Entire length eight inches: length of the bill (from the forehead) three lines and a half, (from the gape) eight lines and a half; of the tarsus six lines; of the tail three inches four lines; from the carpus to the end of the wing five inches ten lines and a half: breadth, wings extended, seventeen inches.
Throat grayish white: all the rest of the plumage above and below sooty black, with greenish reflections: wings and tail extremely long; the latter much forked: tarsi covered with small feathers: irides deep brown: bill and feet black. (Egg). White: long, diam. one inch; trans, diam. eight lines.
Late in its arrival, seldom shewing itself before the beginning, and in some parts of the country not till near the end, of May. Departs also much sooner than the other species of this family; generally about the middle of August. Haunts churches, towers, and other lofty buildings, in the holes of which it breeds. Nest formed of dried grass, and lined with feathers. Eggs two in number. Only one brood in the season. Feeds entirely on insects, taken on the wing. Flight high, and extremely rapid.