The Sea-pie uses its wedge-shaped bill for opening shell-fish with great adroitness; but the industry of the Black Skimmer or Cut-water, (_Rhynchops nigra_,) is still more remarkable. The bill of this bird, which chiefly inhabits the hot coasts of America, is quite unique in its kind; the under mandible, which is in fact nothing but a wedge, being about an inch longer than the upper one, by which it is clasped. The sandy beach of Penco, says Lesson, is full of shell-fish, which remain nearly dry at low water in small pools. The skimmer keeps waiting close by until one of them opens its shell, when he immediately introduces his wedge. He then seizes the mussel, beats it to pieces upon the sand, and devours it with all the pleasure of an epicure eating an oyster. He is also very active in sweeping the surface of the water, from which he skims, as it were, the smaller fish or shrimps. Thus, on all flat sandy shores nothing exists, either soft or hard, creeping or swimming, jumping or running, that does not find among the strand-birds its peculiar and admirably armed enemy, or that can boast of a perfect immunity from hostile attacks. [Illustration: Speckled Diver.] If we examine the real sea-birds, such as are formed for indefatigable swimming or diving, or for wide flights over the deserts of ocean, we shall find them no less wonderfully organised than the winged dwellers on the strand. Their short compressed toes easily cleave the waters, and by means of their membranes or webs form, as it were, broad oars. Their muscular short legs, placed more behind than in other birds, are beautifully adapted for rowing, although their movements on land are awkward and slow. All creatures living on the sea of course require a thick waterproof mantle against weather and storm; and consequently we find the plumage of sea birds thicker, closer, and better furnished with down than that of the other feathered tribes. And finally, the gland which all birds have at the rump, and from which they express an oily matter to preserve their feathers moist, is most considerable among those that live upon the water, and contributes to make their plumage impermeable. Surely the sea bird has no right to complain of imperfect clothing or a deficient outfit! [Illustration: Snow Goose.] The numerous members of the duck family, or the Anatidæ, mostly live during the summer in higher latitudes, and wander in winter in countless swarms towards sunnier regions; as, for instance, the Snow Goose and the Barnacle. Some remain throughout the year in Great Britain, some only during the winter; while others, which are more particularly birds of the Arctic zone, but very seldom make their appearance in our southern clime. Most Anatidæ prefer the lake, the river, the pond, or the morass; but many of them are true littoral birds, and spend a great part of their time swimming and fishing in the sea. [Illustration: Barnacle Goose.]