The contrast is striking between these feathers, the latest being of an almost even shade of pale plumbean with darker centers and generally with a narrow white margin. There are no specimens to show the complete change, but it is probable that these young birds remain on the islands until it is completed. By the middle of June the adults have fully changed to the breeding plumage, but on some specimens a few feathers of the previous winter's plumage persist much later. Thus on many specimens some alternate feathers of the scapulars and tertials are of the previous winter's well-worn plumage. In fact, few specimens are free from these old feathers. Soon after the middle of July the new plumage of the next winter begins to appear. At first a few feathers show about the breast, then on the scapulars, thence up the neck and over the head, so that by the 10th of August they have changed one-half. It would thus appear that before this species leaves the islands they assume entirely their new dress. And at this season, August 10, old and young flock together for the first time, and confine themselves to the sand beaches and surf margins about the islands for a few weeks, when they take flight by the 1st or 5th of September, and disappear until the opening of the new season. The Pribilof sandpiper is much paler in the juvenal plumage and grayer in the winter plumage than the Aleutian. _Food._--Preble and McAtee (1923) report on the contents of 192 stomachs, as follows: The articles of food composing more than 1 per cent of the total were: Mollusks, 32.63 per cent; crustaceans, 29.15 per cent; flies (Diptera), 23.49 per cent; beetles, 10.29 per cent; marine worms, 1.27 per cent; and vegetable matter, chiefly algae, 1.21 per cent. The vegetable matter, besides algae, included bits of moss and a few seeds of grass, lupine, violet, crowberry, and bottle brush. _Behavior._--Referring to the habits of Pribilof sandpipers, Mr. Palmer (1899) says: