Order YITT. ANSERES. Family V. Larid^e. The second Subfamily, RHYNCHOPINiE, or Skimmers, have the mandibles unequal, the upper one always shorter than the lower, which is only received in a narrow groove, their sides suddenly much compressed from the base ; the Wings lengthened, acute, and curved at the tip ; the Tail moderate and forked ; the Tarsi rather longer than the middle toe, and covered with transverse scales ; the Toes moderate, and the anterior partly united by an indented web. Rhynchops Linn.* Bill broad at the base, but suddenly compressed from thence to the tips ; the upper mandible much shorter than the lower, and slightly curved to the tip, which is acute, and grooved beneath to receive the edge of the lower mandible, which is compressed and truncated ; the nostrils basal, lateral, oblong, and pervious. Wings very long, and curved towards the tip, with the first quill the longest. Tail moderate and forked. Tarsi rather longer than the middle toe. Toes moderate, with the lateral ones unequal, and united to the middle toe by an indented web ; the hind toe elevated, and touching the ground with its tip ; the claws long, curved, and acute. The tropical parts of both hemispheres are peculiarly frequented by these birds. They prefer the sheltered inlets and estuaries of the rivers, over the smooth water of which they are observed near the shores at the flood tide, seeking their usual food of small fish and molluscous animals. These they obtain by slowly ploughing along the yielding surface of the prolific sea with the lower mandible, while the upper is elevated out of the water, until the former touches some object that forms a portion of their food, when the two mandibles close together upon it with great rapidity. Their flight is swift and undulating ; when on the ground they walk very awkwardly, and, though they possess webbed feet, they rarely swim or even float on the surface of the water. They seek repose on the strand, or in the neighbouring marshes, but they rest during the day in flocks on the isolated shoals left bare by the recess of the tide. They visit the low sand bars and dry flats of the coast, for the purpose of scratching out a slight hollow in the sands, wherein the female deposits usually three eggs. The female only sits on the nest during the night, or in wet and stormy weather. The young are scarcely distinguishable from the sand, in consequence of the similarity of their colour, and during this period may often be seen basking in the sun, and spreading out their wings upon the warm beach. The parent migrates to the south, as soon as the young are capable of the voyage. 1. R. nigra Linn. PI. enl. 357-, Wils. Amer. Orn. pi. 60. f. 4. — 3. R. albieollis Swains. Two Cent, and a Quart, p 341. Rhynchops borealis Swains.; R. fulva Gmel. ; R. cinerascens et R. 4. R. albirostris Licht. Cat. Dupl. Berl. Mus. p. 80. — Rhynchops brevirostris Spix, A v. Bras. t. 102, 103. flavirostris Vieill. Gal. des Ois. t. 201. ; R. oriental is R iipp., Atlas, 2. R. melanura Swains. Two Cent, and a Quart, p. 340. t. 24. Established in 1756* by Linnaeus (Systema Naturce). In 1760 Brisson proposed Rlu/nchupsalia for the same set of birds. September, 1845.