About the size of a turban snail (1" ish across), and relatively thick-shelled, but looked vaguely like a nautilus. Deep umbilicus (testing out my non-existant mollusk vocab!?). Found in the shell line among a serious amount of rotten kelp and other seaweeds on Mavericks Beach.
Continuing rarity perched on Sail Rock off Pillar Point. Bright white plumage with black wing tips, orange/yellow wash on the head, and distinctive long bill.
There is a fish in the picture near the shell. Found at tide pools near Mavericks, very active moving a lot, found hiding under kelp and shells in the pool.