(Mergus albellus) , of the Old World is the sole representative of its genus, being separated from the remaining genera by the culmen being shorter than the tarsus. The male is a handsome crested bird some seventeen inches long, with the plumage mainly satiny white, relieved by a black patch before and below the eye and a greenish black triangular patch on the crest, while the back is black, the lesser wing-coverts white, and the greater coverts black with two narrow white bars. The female is similar to the male except that the head is reddish brown, the collar ash-gray, and the crest inconspicuous. In early summer the male assumes the plumage of the female, which is retained until fall. The full-plumaged males are said to be very rare, perhaps because they do not approach the shore except in severe weather, while the females and immature young are relatively abundant in winter, especially off the east coast of England and Scotland, where they are called Red-headed Smews by the fishermen. The summer home of the Smew is in the Arctic regions, the western limits of its nesting range being Finnish Lapland. In winter it migrates to southern Europe, northern India, and Japan, and occasionally or accidentally visits eastern North America. Its nest is placed in hollow trees, or in some parts of Lapland in boxes prepared for its use by the people.