Bill straight, grooved on each side, notched, but with no hook at end. Hind toe well developed. Slight web between third and fourth toes, that between second and third obsolete. Mid claw pectinated. Powder-down patches present. In Herons, plumulae of a peculiar kind (the summits of which break off into a fine dust as fast as they are formed) are developed upon certain portions of the integument which are termed " powder-down patches." Tail of ten or twelve feathers. (206-221.)
(i.) Tail of twelve feathers.
(a.) Bare portion of tibio-tarsus equal to or longer than second toe and claw. Edge of mandibles serrated.
Plumage grey or white.