When Delacour and Mayr (1945) revised the classification of the Anatidae, one of their major innovations was the erection of the tribe Mergini, the members of which had in the past (Peters, 193 1) been included in the subfamilies Nyrocinae (=Aythyinae) and Merginae. This separation of the true pochards (Netta and Aythya) from the other diving ducks and the merging of the merganser group into the same tribe with the goldeneyes (Bucephala) and other sea ducks has been accepted by most authorities and incorporated into recent classifications such as those of Kagelmann (1951) and Boetticher ( 1952), although it still is not accepted by the A.O.U. Check-list (1957). However, the eiders, which until 1945 had been included without exception with the scoters (Melanitta), goldeneyes and other diving ducks, were only provisionally placed in the Mergini, since Delacour and Mayr pointed out that the eiders’ tracheal anatomy and the pattern of their downy young differed from those of the other members of the Mergini.
Available at: http://works.bepress.com/paul_johnsgard/195/