71. Diomedea, albatross. Beak straight; upper mandible hooked at the tip, lower abrupt: 2 species.
72. Pelecanus, pelican, gannet, shag. Beak straight, the tip hooked, unguiculate: 8 species.
73. Plotus, darter. Beak straight, sharp pointed, denticulate: 1 species.
74. Phaeton. Beak cultrate, straight, acuminate: 2 species.
75. Colymbus, diver. Beak slender, straight, sharp pointed: 11 species.
76. Larus, gull. Beak straight, cultrate, the tip a little hooked; the lower mandible with an angular prominence: 11 species.
77. Sterna, tern. Beak slender, nearly straight, acute, compressed: 7 species.
78. Rynchops, skimmer. Beak straight; upper mandible much shorter, lower abruptly terminated: 2 species.
Order IV. Grallæ, Waders.
79. Phœnicopterus, flamingo. Beak incurvated as if broken, denticulate; feet webbed: 1 species.