Wings reaching to the rump: bill black, with a transverse white band: a narrow white line in advance of the eye.
A. Torda, Temm. Man. d'Orn. torn. ii. p. 936. Razor-Bill, Mont. Orn. Diet. Bew. Brit. Birds, vol. ii. p. 399. Razor-Bill Auk, Selb. Illust. vol. ii. p. 435. pl. 83.
Entire length seventeen inches: length of the bill (from the forehead) one inch six lines, (from the gape) one inch eleven lines; of the tarsus one inch three lines; of the tail three inches four lines; from the carpus to the end of the wing seven inches six lines.
(Adult in winter). Crown of the head, nape, sides of the neck, and all the upper parts, deep black; from the eye to the middle of the bill a narrow longitudinal interrupted white line: secondaries tipped with white, forming a transverse bar on the wings: throat, front of the neck, breast, and all the under parts, pure white; sides of the occiput white mixed with cinereous, bounded beneath by a narrow black band reaching backwards from the eyes: bill black, with three or four transverse furrows, the middle one pure white: irides hazel: legs dusky. (Adult in summer). The narrow streak from the eye to the middle of the bill pure uninterrupted white: head, throat, and all the upper and fore part of the neck, deep brownish black: the rest as in winter. (Young of the year). Similar to the adult in winter plumage, but easily distinguished by the smaller and narrower bill, without the transverse white furrow: the white line from the bill to the eye obscure and ill-defined: crown and nape cinereous black; sides of the neck, and towards the occiput, white, tinged with ash-colour: under parts pure white. (Egg). White; blotched and spotted with dark red brown and blackish brown: long. diam. two inches nine lines; trans, diam. one inch ten lines.
Like the Puffin, a regular summer visitant. Common on all the rocky parts of the coast during the breeding season, and generally found in large companies. Deposits a single egg, about the beginning of May, on the tops and projecting shelves of the highest cliffs. Food, sprats and other small fish, and marine Crustacea. Obs. The Black-billed Auk of English authors (A. Pica, Gmel). is this species in its immature state.