-135- the world, making it almost impossible to bring a series of any species together for comparison. Chauleasmus cousi. Only known from immature birds; colored like the immature of the ordinary Gadwall, but is much smaller; wing about 8 inches. It is noteworthy that another small duck was later found on Laysan Id., which also has a wing of 8 inches, and possibly the two forms are more closely related than has been supposed; a suspicion that also should include the Hawaiian wyvilliana. Phaethontidae. Tropic-birds. Phaethon aethereus. Red-billed Tropic-bird. Back and scapulars barred with black; outer web of first primary black almost to tip. Phaethon rubricaudus. Red-tailed Tropic-bird. Outer primaries with outer web white to base; middle tail feathers carmine, with black shafts. Phaethon lepturus. A "yellow-billed" species; general color pure white; back uniform, not barred; outer primaries with most of the outer web black to about 1 inch of tip. Sulidae. Boobies. Sula piscator. Red-footed Booby. Sula dactylatra (formerly cyanops). Blue-faced Booby. Sula leucogaster plotus. The Pacific representative of the ordinary booby. Fregatidae. Man-o'-war birds or Frigate birds. Fregata "aquila" or subspecies. Bill 3.6-4.4 inches in male, and