"Dafila. Pin-tail Ducks. Tail (in adult male) narrow, cuneate, when fully developed nearly as long as wing, the 2 central feathers long-exserted, linear-acute: in female and young the tail merely tapering, with acute feathers; tail-feathers 16, including the long middle pair. Bill shorter than head, longer than tarsus, nearly parallel sided, widening a little to the end, the nail small, the narrow nostrils high up in basal third of bill. Feathers of cheeks sweeping in strongly convex outline along side of upper mandible, beyond those on side of lower mandible. Wing acute, the 1st and 2d primaries subequal and longest, rest rapidly graduated. Neck unusually long and slender, and form less "stocky" than that of most ducks. Sexes and young very unlike in color, even to the wing-markings, as well as in shape of tail. Bill and feet dark. Under parts white or whitish." Elliot Coues, 1884

Pin-tail Duck Head

"Dafila. Pin-tail Ducks. Tail (in adult male) narrow, cuneate, when fully developed nearly as long as…