The Eagles, properly so called, are characterized by a head covered with plumage and flattened above; eyes large, lateral, and deep-seated; a bill of great strength, arched and hooked at its extremity alone, and furnished at its base with a naked membrane, called the cere, in which the openings of the nostrils are situated; the wings broad and powerful; the tarsus, or that joint of each leg which is immediately above the toes, strong, short, and covered with feathers down to the very base; the toes thick and naked, three of them pointing forwards, and the fourth constantly directed backwards; and the talons of great power and strongly curved. The Golden Eagle, which occupies the right hand in the cut, is frequently three feet and a half in length from the extremity of the beak to that of the tail. His general colour is blackish brown both above and below, assuming on the legs a grayish or sometimes a reddish tinge. His beak is bluish black, covered at the base by a yellow cere; and his toes, which are also yellow, terminate in strong black talons, the posterior one of which frequently attains an enormous length. He is met with throughout the Old Continent, and more especially within the limits of the temperate zone, building his aiery, which he shares with a single female, in the clefts of the loftiest rock, or among the topmost branches of the alpine forest. From this retreat he towers aloft in search of his prey, which he pursues by sight alone, subsisting principally on other birds and on the smaller quadrupeds, which he carries off in his powerful clutch. When his hunger is extreme he sometimes pounces upon the larger animals; but in such circumstances he is compelled to content himself with sucking their blood upon the spot, and with stripping off portions of their flesh, on which to satiate his appetite at home. Instances have been known of his attaining in captivity to an age of more than a hundred years. The principal distinguishing mark of the group which has been separated under the name of the Sea-Eagles, consists in the plumage of the tarsus, which in the latter extends only half way down, the lower part being consequently left entirely bare. The species figured on the left, at the head of this article, is commonly more than three feet in length, and the expansion of his wings measures seven or eight feet. His bill is usually of a bluish black colour towards the extremity, and yellow at the base. His general hue is blackish brown, deeper above than beneath, and relieved on the breast and under parts by numerous white spots. The larger feathers of his wings are nearly black; but those of the tail are not so deeply tinged. The naked portion of the legs, as also the toes, are covered with bright yellow scales; and the talons are of a bright black.