A large and somewhat varied group of birds known as Shearwaters comprises principally the second subfamily (Puffininae), deriving their popular name from their habit of gliding along very close to the surface of the water, and their scientific designation from the mistaken notion that they were Puffins. They are strong-flying Petrels, with long, slender bills in which the nasal tubes are united externally, or nearly so, above the culmen, and with long, pointed wings. They are found on practically all of the seas of the world, though ordinarily at no great distance from land, to which, however, they rarely resort except for nesting purposes. Some twenty-five species have been described, of which number North America lays claim to ten or more; but as the differences between the species are not very strongly marked and the habits very similar, it will only be necessary to select a few of the more important. One of the largest species is the Great Shearwater or Hagdon (P. major) of the Atlantic Ocean generally, a bird nineteen or twenty inches long, having the upper parts fuscous, with the wings and tail slightly darker, while the under parts are white, becoming ashy gray on the abdomen and under tail-coverts. It is exceedingly abundant in many parts of the Atlantic, especially off the coast of Newfound-land, where Palmer speaks of seeing them in thousands sitting on the water. Brewster says of its flight : “It usually follows a direct course, and invariably skims close over the waves. I know of no other sea-bird whose movements are so easy and graceful. Indeed, at times, especially during a gale, its evolutions will compare in grace and spirit with those of the Mississippi or Swallow-tailed Kites.” Its nest and eggs are unknown. Of the four species found in the British seas the Manx Shearwater (P. puffinus) is the most abundant and best known. It is much smaller than the last, being only about fifteen inches long, and is sooty black above and white below, with the sides of the neck mottled with grayish brown. It breeds at several stations in the Channel and along the west coast of Great Britain, as well as a few islands of the Irish coast, but the principal colony is on St. Kilda, often called the sea-birds’ paradise. Its favorite breeding places are the islands with a good ocean aspect, especially such as are broken in grassy downs, and fall in crags and precipices more or less turf-grown. Their burrows are made in the steep, grassy parts of the cliff or near their summit, and many nests are made close together, sometimes one main entrance leading to several burrows, each containing a nest. The birds are strictly nocturnal during the nesting season, but in winter they are said to feed at all hours. Other species of more or less common occurrence in the Atlantic are Audubon’s Shearwater (P. lherminieri) and the Sooty Shearwater, or Black Hagdon (P. fuliginosus),both very dark or sooty above. On the Pacific coast of the United States there are a number of species, perhaps the most abundant being the Black-vented Shearwater (P. opisthomelas) of southern California. About fourteen or fifteen inches long, it has the upper parts a uniform sooty slate, paler on the head and neck, and the under tail-coverts wholly sooty grayish. According to Mr. A. W. Anthony, it is extremely abundant off the coast of central California in summer, and is found at all seasons of the year south of the Santa Barbara Islands. It has been found breeding on San Benito Islands, all the nests being in small caves, and on Natividad Island, an island some thirty-five miles south, where they excavate burrows often ten feet in length. Other wellknown species are the Dark-bodied Shearwater (P. griseus), Townsend’s Shearwater (P. auricularis) of Clarion Island and western Mexico, and the Wedge-tailed Shearwater (P. Ccuneatus), a species supposed previously to range from the Hawaiian Islands to the Bonin Islands, south of Japan, but which Mr. Anthony has found to be abundant off Lower California in May and June. Another species of wide range is the Slender-billed Shearwater (P. tenuirostris) which ranges from the seas about Australia and New Zealand to Alaska and Japan. It is very abundant about New Zealand and retires inland, sometimes for fifty miles, to breed.