Head of moderate size, neck rather long and slender, body full and depressed, wings rather small. Feet very short, strong, placed rather far behind; tarsus very short, compressed, at its lower part anteriorly with two series of scutella, the rest covered with reticulated angular scales. Toes scutellate above, first very small, free, with a broad membrane beneath, fourth longest, third scarcely shorter; claws small, curved, compressed, obtuse, the hind one smaller, more curved and acute, that of the third toe with an inner sharp edge.
Plumage dense, soft, blended, rather glossy. Feathers of the middle of the head, and upper part of hind neck, very narrow and a little elongated; of the rest of the head and upper part of the neck very short, of the back and lower parts in general broad and rounded. Wings of moderate length, narrow, acute; primaries curved, strong, tapering, first longest, second very little shorter; secondaries broad, rounded, short, the inner longer and tapering. Tail very short, rather broad, much rounded, of sixteen rounded feathers.
Bill black, with a basal band, the edges of both mandibles, and a band across the upper towards the end, pale blue. Iris yellow. Legs greyish-blue, the webs brownish-black. The head, and upper part of the neck, greenish-black, with purple reflexions. A brownish-red collar, broader before, on the middle of the neck. Its lower part all round, as well as the back, scapulars, smaller wing-coverts, and posterior part of abdomen, brownish-black. Inner secondaries of the same colour, outer bluish-grey on the outer web, light brown on the inner, as are the primaries, of which the outer webs and tips are dark brown. Tail brownish-grey. Chin white, breast greyish-white, sides and fore part of abdomen greyish-white, minutely undulated with greyish-brown.
Length to end of tail 18 inches, to end of wings 16; extent of wings 28; wing from flexure 7 3/4; tail 2 1/2; bill along the back 2 1/12, along the edge of lower mandible 1 11/12; tarsus 1 4/12; middle toe 2 2/12, its claw 4/12.
Adult Female. Plate CCXXXIV. Fig. 2.
The Female has the neck umber brown, the upper part of the head darker, the back blackish-brown, the speculum bluish-grey, as in the male, the breast brownish-white, the loral spaces and chin pale brown, the abdomen umber brown.
Length 16 inches.
The Tufted Duck of Europe, Fuligula cristata, is very intimately allied to this species. The bill of the latter is longer, narrower, and differently coloured, the unguis broader at the end, as is the flat triangular space at the base of the upper mandible. The bill of the Scaup Duck is still broader towards the end, with a much narrower unguis, and the flattened part of the upper mandible still narrower than in the Tufted Duck; the colour of the speculum is also different, being bluish-grey in the Ring-necked Duck, and white in the two allied species. The females of the Ring-necked and Scaup Ducks, which are nearly similar in colour, differ in the speculum, and in the peculiar form of the bill.
THE SOOTY TERN.
Sterna fuliginosa, Lath.
PLATE CCXXXV. Male.