I. Gallinaceæ (Polygamous), Pea-fowl, Partridge, Pheasant, Quail, Grouse, Pentados, Turkey, Curassow.
II. Columbaceæ (Monogamous), Pigeons, Gouravinago.
IV. Cantores.
Singing birds. Legs short and slender, three toes before and one behind. In this order, according to Professor Owen, the brain attains its greatest proportionate size, and the organs of the voice their greatest complexity.
I. Dentirostres, Shrikes, Wrens, Wagtails, Thrushes, Warblers, Manakins.
II. Conirostres, Birds of Paradise, Crows, Tits, Starlings, Buntings, Larks, Finches, Grosbeaks.
III. Tenuirostres, Nuthatch, Creeper, Sunboard.
IV. Fissirostres, Swallows, Martins.
V. Volitores.
Birds moving solely by flight. Skeleton light and buoyant; head large; keel deep (entire on the Humming-bird); wings powerful, in some long and pointed; legs small and weak. The order includes—
I. Cypselidæ, Swifts.
II. Trochilidæ, Humming-birds.
III. Caprimulgidæ, Night-jar.
IV. Trogonidæ, Trogons.
V. Prionitidæ, Momots or Motmots.
VI. Meropidæ, Bee-eaters.
VII. Galbulidæ, Jacmar.
VIII. Coraciadæ, Rollers.
IX. Capitonidæ, Puff-bird.
X. Alcedinidæ, King-fishers.
XI. Bucerotidæ, Hornbills.
VI. Scansores.
Climbing birds, with opposing toes in pairs, two behind and two before. The order includes—
I. Ramphastidæ, Toucans.
II. Bucconidæ, Barbets.
III. Cuculidæ, Cuckoos.
IV. Picidæ, Woodpeckers.
V. Musophagidæ, Plantain-eaters.
VI. Coliidæ, Colys.
VII. Psittacidæ, Parrots.