Water birds with tarsus extremely flattened and legs set far back on
body; neck long; plumage dense; tail-feathers very short and soft;
toes lobed; toes and nails very broad and flat; hind toe small and
elevated. Eggs with a white chalky surface; nest a mass of reeds near
the water often floating on the water.
Family COLYMBIDÆ.
Characters same as those given for the Order.