Above brownish black; secondaries tipped with white: bill as long as, or somewhat longer than, the head; very much compressed throughout: feet dusky.
U. Troile, Temm. Man. d'Orn. torn. 11. p. 921. Foolish Guillemot, Mont. Orn. Diet, & Supp. Bew. Brit. Birds, vol. 11. p. 166. Selb. Must. vol. 11. p. 420. pl. 79.
Entire length seventeen inches nine lines: length of the bill (from the forehead) one inch eleven lines, (from the gape) two inches eleven lines; of the tarsus one inch seven lines; of the tail two inches; from the carpus to the end of the wing six inches two lines: breadth, wings extended, two feet.
(Adult in winter). Forehead, crown, space between the eye and the bill, a longitudinal streak running backwards from the eyes to the distance of an inch and a half, and all the upper parts, including the wings, brownish black with a slight tinge of cinereous: occiput grayish white, opening on each side into a white patch above the longitudinal streak behind the eyes: secondaries tipped with white: all the under plumage pure white; the black on the sides of the neck advancing in front towards the lower part, and forming a faint collar of grayish ash: bill black; very much compressed throughout its whole length: inside of the mouth dull yellow: irides brown: feet and toes yellowish brown; posterior part of the tarsus and membranes black. (Summer plumage). The whole of the head, including the region of the eyes, throat, and all the upper part of the neck, pitchy brown: inside of the mouth bright yellow: the rest as in winter. (Young of the year). Resemble the adult in winter, but distinguished by the shorter bill: the longitudinal streak behind the eyes is also indistinct; and the white on the under parts less pure, with more of cinereous brown on the lower part of the neck: tarsi and toes dull yellowish; membranes brown. (Egg). Very variable in colour, scarcely two being found precisely alike; generally bluish green, more or less blotched and streaked with black: long. diam. three inches two lines; trans, diam. one inch eleven lines.
Met with in great abundance on various parts of the British coast throughout the year. Breeds on cliffs and rocky islands, generally in large companies. Lays a single egg. Food, fish, marine insects, and small bivalve mollusca. Obs. The Lesser Guillemot of English authors is the young of the year of this species.
Trans, vol. xii. p. 538. Temm. Man. d'Orn. torn. 11. p. 924. Franks' Guillemot, Shaw, Gen. Zool. vol. xii. p. 243. pl. 62.
According to the statement of a writer in the Quarterly Review, (vol. xlvii. p. 354). this species has been killed off one of the Shetland Isles. It is distinguished from the last, principally by the form of the bill, which is shorter and more dilated at the base.