385. 2. Cygnus Americanus, Sharpless. American Swan. Plate CCCCXI. Male. Tail feathers twenty; bill and feet black, the former with a small orange spot on each side at the base; plumage pure white. Young grey. _Male_, 53, 84. Common during winter in the Middle Atlantic Districts, especially on Chesapeake Bay. Not seen south of Carolina. Columbia River. Breeds in the Fur Countries. American Wild Swan, Cygnus americanus, Sharpless, Amer. Journ. of Sc. and Arts, v. xxii. American Swan, Cygnus americanus, Aud. Orn. Biog. v. v. p. 133. GENUS IV. ANAS, Linn. DUCK. Bill about the length of the head, somewhat higher than broad at the base, depressed and widened towards the end, rounded at the tip; upper mandible with the dorsal line sloping, and a little concave, the ridge at the base broad and flat, towards the end broadly convex, as are the sides, the edges soft and rather obtuse, the marginal lamellæ numerous, oblique; unguis decurved, obovate; nasal groove elliptical, subbasal, filled by the soft membrane of the bill; lower mandible flattened, slightly recurvate, with the angle very long and narrow, the unguis roundish, the lamellæ numerous. Nostrils subbasal, elliptical, near the ridge. Head of moderate size, oblong, compressed; neck rather long and slender; body full, depressed. Feet short, stout, placed a little behind the centre of the body; tibia bare a little above the joint; tarsus short, somewhat compressed, anteriorly with small scutella, laterally and behind with angular scales; hind toe extremely small, with a very narrow membrane; third toe longest, fourth a little shorter, but longer than second; all covered with numerous oblique scutella; anterior connected by reticulated membranes. Claws small, arched, compressed, rather acute. Plumage dense, soft. Wings of moderate length, acute; second quill longest, first very little shorter; inner secondaries elongated and tapering; tail short, much rounded, of sixteen feathers. Œsophagus rather narrow, dilated on the lower part of the neck; stomach an extremely muscular, transversely elliptical gizzard; intestine long and rather wide; cœca long. Trachea of the males, with a transverse bony unsymmetrical dilatation at the inferior larynx. 386. 1. Anas Borchas, Linn. Mallard. Plate CCXXI. Male and Female.