71. Sula (Gannet). Bill straight, longer than the head, compressed, tapering to a point, which is but slightly curved; face and throat naked; inner edge of the middle claw serrated; tail graduated.
ORDER HERODIONES
Hallux free, not united to other toes by a web.
FAMILY ARDEIDÆ
(Herons)
Hind toe on same plane as others. Bill rounded or ridged; notched, with no hook at end. Outer toe with broad basal web, obsolete at base of inner toe; middle claw pectinated, loral space bare; powder down patches present.
72. Árdea (Herons). Edges of mandibles distinctly serrated; head crested; nape feathers elongated and ornamented; plumes of fore-neck not disintegrated; no dorsal train.