Of great stature, with extraordinarily lengthened neck and legs. Bill of unique shape, bent abruptly down from the middle. Tibiæ naked below. Hind toe minute or absent. Wings rounded. Red the chief color … _Phœnicopteridæ_. Of moderate size; the neck short, or, when lengthened, not accompanied by co-ordinately lengthened legs, these being always shorter than the wing. Bill straight. Tibiæ feathered below. Hind toe present; well developed and functional, though short … _Anatidæ_. ANALYSIS OF FAMILIES OF STEGANOPODES. Bill rather longer than head, cleft to eyes, very stout at base, tapering to the decurved, but not hooked, tip. Nostrils abortive. Gular sac moderate, naked. Wings rather long, pointed. Tail long, stiff, cuneate, twelve to fourteen feathered. Feet nearly beneath centre of equilibrium. General configuration goose-like … _Sulidæ_. Bill several times longer than head, slender but strong, depressed, perfectly straight, with small distinct hooked nail at end. Nostrils very small. Gular sac enormous. Mandibular rami meeting only at tip. Wings extremely long, with upward of forty remiges. Tail short, rounded, of twenty or more feathers. Legs beneath centre of equilibrium, extremely short and stout … _Pelicanidæ_. Bill about as long as head, stout, straight, scarcely tapering, strongly hooked. Nostrils abortive. Gular sac moderate, but evident; mostly naked. Wings short. Tail large, fan-shaped, scansorial, of twelve to fourteen broad stiff feathers, exposed to the base. Legs inserted far behind centre of equilibrium … _Graculidæ_. Bill rather longer than head, slender, perfectly straight, tapering to an acute tip. Gular sac small. Nostrils minute. Wings and tail, and general configuration, as in the last … _Plotidæ_. Bill much longer than head, straight, stout, strongly hooked. Nostrils very small. Gular sac well developed. Wings exceedingly long, strong, and pointed. Tail exceedingly long, deeply forked. Feet extraordinarily short; tarsi partly feathered … _Tachypetidæ_. Bill about as long as head, straight, stout, tapering to an acute tip. Nostrils small. Gular sac rudimentary, feathered. Wings moderate, pointed. Tail short, but with two central feathers extraordinarily prolonged and filamentous. Feet small, beneath centre of equilibrium … _Phæthontidæ_. ANALYSIS OF FAMILIES OF LONGIPENNES. Nostrils not tubular, lateral, perforate. Bill with continuous covering, or only broken by a sort of cere, hooked or straight to the end. Hallux small and elevated, but always present … _Laridæ_.