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.