This well-marked genus may be recognized by its elongate form, long neck, and long pointed middle tail-feathers.

161. DAFILA ACUTA (Linnæus).
PIN-TAIL DUCK.

Luzon (Steere Exp., Bourns & Worcester, McGregor). Northern Hemisphere, breeding in the northern parts; south in winter to northern Africa, India, Ceylon, China, and Japan and in America to Panama and Cuba.

“Adult male.—Head and upper neck plain hair-brown, darker on crown, and faintly glossed on sides of occiput with purple; upper half of hind neck black, with a white stripe on each side, confluent with the white of lower neck and breast; lower hind neck grayish brown; back, sides, and flanks waved with gray and dusky; upper tail-coverts black, the median broadly edged with gray; longer scapulars velvety black, edged with whitish; wing-coverts uniform brownish gray, the last row broadly tipped with cinnamon, producing a distinct bar; primaries brownish gray, darker toward the tip; speculum varying from dull metallic green to bronzy purple, tipped with white, and crossed by a subterminal bar of velvety black; inner quill of the speculum velvety black with a white band along the inner part of outer web; tertials gray, marked with a velvety black median stripe; abdomen whitish, dusted with gray, lower flanks with a buff tinge; under tail-coverts black, the outer ones white on the outer web; central tail-feathers long, acuminate, and black, remainder of tail-feathers dusky gray, edged with whitish. Bill blackish, with the sides dull lead-blue; feet grayish black; iris dark brown. Length, from 610 to 760; wing, 280; middle tail-feathers, 184 to 240; culmen, 47 to 55; tarsus, 39 to 47.

“‘Adult female.—Above grayish dusky, varied with irregular bars of yellowish white or pale ochraceous; head and neck whitish buff, each feather, except on throat, streaked with blackish; lower parts dingy white, flanks, abdomen, and under tail-coverts streaked with dusky; wing brown, smaller wing-coverts tipped with whitish; greater wing-coverts and secondaries tipped with white, forming two white bars across the wing, but the space between them dull brown, mottled with black, without any metallic gloss of any kind.’ (Seebohm.) Tail brown with oblique buffish spots or bars. Length, 533 to 597; wing, 244 to 256; middle tail-feathers, 114 to 127; culmen, 46 to 53; tarsus, 42.

“‘Young in first plumage closely resembles adult females, but young males may always be distinguished by having an alar speculum.

“‘Males in first nuptial plumage have pale margins to the wing-coverts, and most of the feathers of the rump are broadly barred, instead of finely vermiculated, with white.

“‘Adult males in molting plumage may be distinguished from adult females by having an alar speculum, and being richer and darker in color.