Petrels resemble gulls, except in having the nostrils open as two parallel tubes on the top of the beak.
"Sterna aleutica. Aleutian Tern. Bill of ordinary shape, as in hirundo, macrura, etc., entirely black.…
"Sterna dougalli. Roseate Tern. Paradise Tern. Bill about as long as head or foot, straight, slender,…