Ardeola, diminutive of Ard$a. Ardea, oe, f. =—a Heron (Virgil, Georg.. i. 364).
Head, neck, and hack always coloured, but colour changes completely at breeding season. Wings, body, and tail white. Long ornamental nape-plumes. Tibia feathered to the knee nearly. Dorsal train well developed. Confined to the Old World.