Adult male in nuptial plumage of _A. platyrhynchos_ type: "Whole head is dark green, except at the sides where buff feathers are plentifully intermingled, a dark brown streak through the eye, and faint white ring on the lower neck. Feathers on scapulars and sides of body are as those of _Anas poecilorhyncha_. Sides of body are vermiculated but some brown feathers are found even in the full nuptial plumage. Upper breast is dark reddish chestnut with dusky spots. Upper and under tail-coverts are as in _Anas platyrhynchos_. Speculum is as that of _Anas platyrhynchos_, but the tips of the greater coverts are buff instead of white. Central tail feathers are more or less curled upward. Base of bill is black, tip is olive color. Iris is dark brown. Feet, reddish-orange, webs darker." Eclipse plumage of adult male resembles that of _A. platyrhynchos_. Adult male in nuptial plumage of _A. poecilorhyncha_ type: "Resembles _Anas poecilorhyncha pelewensis_ from the Palau Islands and Truk Island, but sides of head are browner, superciliary stripes and ground color of cheeks are more buffy. Feathers on upper breast and sides of body are more broadly edged with brown. Speculum is usually violet-purple as in the _platyrhynchos_ type, but in two specimens from Saipan and Tinian, respectively, it is dark green as in _Anas poecilorhyncha pelewensis_. Tips of the secondaries are usually white, but sometimes very faint as in _Anas poecilorhyncha pelewensis_, and in one specimen from Saipan they are buffy. Bill is olive color with a black spot in the center of the upper mandible. Iris, dark brown. Feet, dark orange, darker in joints and webs." Eclipse plumage of adult male resembles the nuptial plumage. _Measurements._--Measurements of nine ducks from Guam and Saipan are: wing, 238-266 (252); tail, 75-84 (81); exposed culmen, 49-53 (51); tarsus, 41-43 (42). _Specimens examined._--Total number, 9 (5 males, 2 females, 2 unsexed), as follows: Mariana Islands, USNM--Saipan, 2 (Oct. 2, 3)--Guam, 1 (June 6); AMNH--Saipan, 2 (Aug. 7, 11)--Guam, 4 (Jan. 10, April 6, Dec. 11, 16).