of the United States. 38 1 ? 
Macreuses , Garrots, Eiders , Millouins , Cmil Clangula, Me- 
lanilta , Somateria , Aythya , Boie. 
Bill broader than high at base, not of equal breadth 
throughout, somewhat flattened, much depressed towards 
the point, obtuse; upper mandible convex, curved and un- 
guiculated at tip, nail slender ; lower narrower, flat : nostrils 
basal or medial, oval, open, pervious, covered by a mem- 
brane ; tongue fleshy, thick, broad, fimbriated on the sides, 
obtuse. Head thick, wholly feathered ; neck stout, much 
shorter than the body : body plumpish. Feet placed very 
far back, large and stout ; tibia partly covered by the skin 
of the belly, furnished before with an acute prominence; tarsi 
much shorter than the middle toe, extremely compressed ; 
toes rather long, middle one longest ; inner shorter than the 
outer ; webs full, entire, very broad ; hind toe equal to a 
phalanx of the middle one, furnished with a membrane, touch- 
ing the ground at tip. Wings shortish ; quills very stiff ; 
first and second primaries subequal. Tail stiff, of from 
twelve to eighteen feathers. 
Female very different from the male. Male hardly chang- 
ing from season. Young similar to the female, not assuming 
their adult dress before the second or third year. Moult 
twice a year without changing their colors. Plumage short, 
not so light, but closer and thicker than in the preceding 
genus. Capsule of the windpipe of the male much larger. 
Migrate in large flocks. Found mostly in the north, affect- 
ing in autumn and winter, the sea shore and brackish water ; 
fond of deep water, enjoying even the most boisterous sea. 
Swim and dive with great agility, and make long distances 
under water, diving for food or in sport. Somewhat noctur- 
nal ; feed and travel by night. Food chiefly animal, espe- 
cially mollusca, also a few vegetables, after which they dive. 
Strictly monogamous : build chiefly on fresh water : nest 
downy within : eggs numerous. Female only sits, and 
leads her young to the water as soon as hatched, after food. 
