Color Key to North American Birds / with bibliographical appendix

by Frank M. Chapman

Family 10. GANNETS. Sulidæ.

Bill stout, its tip not hooked; chin and eye space bare; tail pointed, its feathers not 'fluted.'

Family 11. ANHINGAS; SNAKE-BIRDS. Anhingidæ.

Bill straight and slender; chin and eye space bare; tail rounded; its middle feathers fluted.

Family 12. CORMORANTS. Phalacrocoracidæ.

Bill with a hooked tip; a small pouch at its base; plumage usually black or blackish.