The _Bernicle_, or Tree Geese, are so called from a foolish tradition of the Middle Ages of their being produced from the barnacle shell which attaches itself to ships' bottoms and timber floating in the sea. They differ from the true Geese in having the head smaller, the bill shorter and more conical, the breast-feathers much larger, and in the predominance of black in their plumage, bills, and feet. The plumage is full, very soft, and close. There are several species of _Bernicla_, which some recent writers have formed into a genus under that somewhat inappropriate name, the best-known species being the White-faced or Bernicle Goose, _Anser leucopsis_, Temminck, and the Black-faced or Brent Goose, _Anser bernicla_, of the same author. THE WHITE-FRONTED BERNICLE GOOSE. ENGLISH SYNONYMS.--Bernicle Goose: Selby, Montagu. White-faced Bernicle Goose: McGillivray. Common Bernicle: Jenyns. Clukis: Selby. LATIN SYNONYMS.--_Anas bernicla_: Linn. _Anas erythropus_: Latham. _Anser leucopsis_: Temminck, Jenyns. _Anser bernicla_: Selby. _Bernicla leucopsis_: Bonaparte, McGillivray. FRENCH SYNONYM.--_Oie bernache._ In its winter plumage this is a beautiful Goose, much smaller than those just described, but with a full body, long neck, and a small, oblong, and compressed head, with soft glossy plumage well blended on the head, neck, and breast. It occurs in considerable flocks in the Outer Hebrides, where it arrives in October, and remains till April. A large flock of these birds sitting lightly on the water, advancing with elevated necks, presents a very beautiful spectacle. Nor are they less handsome on the wing as they shoot through the air, now arranged in long undulating ranks, at one time extending in the direct line of their flight, at another flying obliquely, or at right angles to it, and again mingling altogether under some unexplained impulse. Their voice, as it proceeds from a large flock at some distance off, is clear and shrill, producing a pleasant harmony. The Brent Goose, or Black-faced Bernicle, is much smaller than the _Anser leucopsis_, and easily distinguished from it by the face and head being entirely black. They seem to have visited our shores in great numbers in former years. In the years 1739-40 these birds were so abundant on the French coast that the people rose _en masse_ to destroy them, and so numerous on the Kentish coast that many were taken in a starving condition. Mr. McGillivray met with large flocks of them in Cromarty Bay, Beauley Firth, and Montrose Basin. Mr. Selby observed them as constant visitors on the shallow waters between Holy Island and the mainland, and other parts of the coast. [Illustration: Fig. 98.--White-fronted Bernicle Goose (_Anser erythropus_).] THE SWAN (_Cygnus_).