Larus glaucescens 5 Feb. 1958 Red Rock Island, San Francisco Bay Calif. Found adult bird dead on beach. It was pretty fresh, no smell or slipping. Feet are pink, bill pale yellow with orangish spot near and lower mandible. Head, neck and entire underparts white, as is tail and all tail coverts. Mantle light gray, leading edge of wing white. Flight feathers tipped with white. primaries q=gray, rest white. Saved skull and left foot. Bird was F, many over about 1mm or less.