Under this name we class numerous families, all of which are more or less distinguished for the perfection of their vocal apparatus. In appearance the members of this order are for the most part pleasing and elegant, and their disposition usually attractive and engaging. Their body is long, the neck short, and their head comparatively large; the beak, though differing much as to its formation, is almost invariably small, straight, or only very slightly curved, and the upper mandible is generally more or less incised; the tarsi are covered with horny plates, the toes long, and the claws large and sharp; the wings, invariably of moderate size, are formed of ten quills, the first of these being usually much stunted or not at all developed; the tail is by no means large, and composed of twelve feathers. The plumage, which is soft, thick, and occasionally downy in texture, is simple and uniform in its coloration; some few species, however, are brilliantly ornamented. The young at first differ considerably in appearance from the adult birds, and both young and old moult their feathers once within the year. All the members of this extensive order are active, intelligent, and extremely restless; their flight is light and rapid, and their movements amongst the branches or upon the ground are distinguished by extraordinary agility. In all, the sight and hearing are very perfect. They live chiefly upon insects and seeds of various kinds, but some few species will kill and devour small birds or similar prey. Every part of the world is enlivened by the presence of these delightful warblers, whose cheerful voices are heard even in the most dreary and desolate regions, on burning, sandy plains, as well as upon the ice-bound shores of arctic regions. Such as inhabit tropical climates do not migrate; but those within the temperate zones, as winter approaches, remove towards the south, seeing that their native lands at that season do not afford them a sufficient supply of food. Very great variety is observable in the construction of the nests built by different species of singing birds, many exhibiting wonderful skill, and in some cases actually _sewing_ together the materials they employ, with their sharp beaks, whilst others are contented to drag a few leaves into a hole and thereon deposit their brood. The eggs, sometimes five or six in number, are hatched by the agency of both parents, who also assist each other in procuring food for the young progeny. The latter grow with great rapidity, and are capable of providing for a family of their own after the first year. * * * * * The TOOTH-BEAKED SINGING BIRDS (_Dentirostres_) constitute a large tribe, the members of which are at once recognisable by a notch or tooth at the extremity of the upper mandible. * * * * *