I especially liked the teeming zoo I found under a looseleaf-sized thin slab of red slate. It was dense with tiny mussels, hermit crabs the size of peas, and weird worms that I think were sand or pile worms. (A field guide suggested gently pressing the worm behind its head to cause it to evert its "sharp black pincers," a suggestion I found it easy to ignore.)
The best critter hidden under the slab was a rockweed isopod, a marine cousin of the pill bug and the sow bug (those little gray army-tank minibeasts that live in your yard and are sometimes called roly-polies or potato bugs). This one, as you can see, was bright olive green.
Apparently the isopod wears this color most frequently but can also be black, pink, or tan, depending on what color its background is. It's also called Vosnesensky's isopod. Which is a lot of name for a little guy like this to tote around, even if it can grow to be 2 inches long.
Vosnesensky was some Russian guy who studied marine isopods on the west coast in the mid-1800s. And he got to have one named after him. Some people have all the luck.
The birds were out in force, too. Crows poked and probed at the rocks, as did gulls, feasting on the bounty laid out by the extra-low tide. A bald eagle circled over the beach. The song of a Swainson's thrush spiraled up from the woods, and this cheerful song sparrow piped away in a shrub near the entrance to the beach.