ORDER 2. LONG-WINGED SWIMMERS.—Longipennes.
SKUAS, JAEGERS. Family Stercorariidæ:—Marine birds of prey; bill strongly hooked, with long scaly shield, or cere, at the base; claws strong and curved, hawk-like; flight hawk-like; plumage often entirely sooty-black, and always so on the back.
GULLS, TERNS. Family Laridæ:—Gulls have hooked bills, usually yellowish, yellow eyes and pale, webbed feet. Heap, underparts and square tail are white in adults; back, pearl-grey; exceptions are the four small black-headed gulls, which also have reddish legs. Gulls fly with the bill straight in front, and often rest on the water. Terns have forked tails, black caps, and their slender, pointed bills and small webbed feet are usually red. They fly with bill pointed down, and dive upon their prey.