The PUFFINS (_Puffini_) are recognisable by their slender bodies, proportionately short wings, and more or less rounded tail, composed of twelve feathers. The beak is short, or of moderate length, and the nostrils divided. The legs are large, broad-footed, and placed very far backwards. The plumage is smooth and oily. The Puffins are eminently aquatic birds, only visiting the land for the purpose of hatching and rearing their young; nevertheless they often approach the shore or visit harbours on the coast. They are generally met with in little flocks consisting of from eight to twenty individuals, and employed in fishing for food. During the breeding season, however, they assemble in such vast numbers as almost to cover the rocks on which they build. Their food consists principally of fishes and molluscous animals, which are invariably caught by diving. The Puffins are distinguishable from all their allies by the impetuosity of their flight. Sometimes they may be seen swimming quietly upon the water and diving into the advancing waves; generally, however, they are observed flying, and not only shooting over but dashing through them. With outstretched wings they plunge into the billows, urging their career with rapid strokes, twisting and turning in the water, not only sideways but completely round, so that sometimes the dark-coloured back, sometimes the shining white under surface becomes visible; now they seem to follow the outline of the wave, climbing upon one side of it and plunging down the other as they suddenly emerge from the water, and, after rising ten or twelve feet into the air, once more plunge obliquely into the sea, where they again dive, rowing themselves along with feet and wings till, after making their way to a considerable distance, they come up into the air, apparently simply to take breath, and forthwith disappear in the same manner. The interest attaching to this spectacle is considerably increased from the circumstance of so many of the birds joining in these active evolutions, just as one plunges beneath the surface another emerges, and as they are all busily employed, it is difficult for the eye to follow their rapid evolutions. Although the Puffins do not congregate around their breeding-places in such vast multitudes as other water-fowl, they regularly visit St. Kilda and other places among the Hebrides and Faroe Islands in very considerable numbers, generally arriving in the night, during which they appear to be even more active than in the daytime.