Family 15. DUCKS, GEESE, AND SWANS. Anatidæ.
Bill long, narrow, and rounded with tooth-like projections along its sides. (Mergansers. Subfamily Merginæ.)
Bill broad, flattened, typically duck-like; tarsus or leg with transverse scales; hind toe without a lobe. (River Ducks. Subfamily Anatinæ.)
Bill and tarsus as in preceding, but hind toe with a broad lobe or flap. (Sea and Bay Ducks. Subfamily Fuligulinæ.)
Bill proportionately narrower than in the River or Bay Ducks; gutters on its sides less developed; scales on front of tarsus rounded. (Geese. Subfamily Anserinæ.)
Large, usually white birds, with bare eye space. (Swans. Subfamily Cygninæ.)
Order VI. Flamingoes. ODONTOGLOSSÆ.
(1 family, 1 species.)