Anas marila, Linn. Syst. Nat. vol. i. p. 196.—Lath. Ind. Ornith. vol. ii. p. 853.
Fuligula marila, Ch. Bonaparte, Synopsis of Birds of the United States, p. 392.—Swains. and Richards. Fauna Bor. Amer. part ii. p. 453.
Scaup Duck, Anas marila, Wils. Amer. Ornith, vol. viii. p. 84. pl. 69. fig. 8.—Nuttall, Manual, vol. ii. p. 437.
Adult Male. CCXXIX. Fig. 1.
Bill as long as the head, deeper than broad at the base, enlarged and flattened towards the end, which is rounded, the frontal angles narrow and pointed. Upper mandible with the dorsal line at first straight and declinate, then slightly concave, along the unguis curved, the ridge broad at the base, narrowed at the middle, enlarged and convex towards the end, the sides nearly erect at the base, becoming more and more declinate and convex, the edges curved upwards, with about forty lamellæ, the unguis small and oblong. Nostrils submedial, oblong, rather large, pervious, near the ridge, in an oblong groove with a soft membrane. Lower mandible flat, with the angle very long and rather narrow, the dorsal line very short and straight, the erect edges with about sixty lamellæ,—on the upper edge, however, the lamellæ are more numerous,—the unguis broadly elliptical.
Head of moderate size. Eyes small. Neck of moderate length, rather thick. Body comparatively short, compact, and depressed. Wings small. Feet very short, strong, placed rather far behind; tarsus very short, compressed, anteriorly with a series of broad scutella, externally of which is another of smaller, the rest reticulated with angular scales. Hind toe small, with a free membrane beneath; anterior toes double the length of the tarsus, united by reticulated membranes having a sinus at their free margins, the outer and inner with loose somewhat lobed marginal membranes, all obliquely scutellate above, the third and fourth about equal and longest. Claws small, that of first toe very small and curved, of middle toe largest, with an inner thin edge, of the rest very slender and pointed.
Plumage dense, soft, blended. Feathers of the head and neck short and velvety, those of the hind head a little elongated. Wings shortish, narrow, pointed; primary quills curved, strong, tapering, the first longest, the second very little shorter, the rest rapidly graduated; secondary broad and rounded, the inner elongated and tapering. Tail very short, much rounded, of fourteen feathers.
Bill light greyish-blue, the unguis blackish. Iris yellow. Feet greyish-blue, the webs and claws black. The head, the whole neck, and the fore part of the back and breast black, the head and neck glossed with purple and green, the rest tinged with brown. Hind part of the back, rump, abdomen, and upper and lower tail-coverts brownish-black. Middle of the back, scapulars, inner secondaries, anterior part of abdomen, and sides greyish-white, beautifully marked with undulating black lines. Middle of the breast white, wings light brownish-grey. Alula, primaries at the base and end, and the greater part of secondaries, brownish-black; the speculum on the latter white.
Length to end of tail 16 1/2 inches, to end of claws 18; extent of wings 29; wing from flexure 8 1/4; tail 2 1/4; bill along the back 1 10/12, along the edge of lower mandible 2; tarsus 1 1/4; middle toe 2 2/12, its claw 5 1/2/12. Weight 1 lb. 6 oz.
Adult Female. Plate CCXXIX. Fig. 2.