The striped shell is the shield limpet. For more information on the habitat, vegetation, and weather of this beach, please see the journal entry for May 13, 2012 here on iNaturalist. I only saw a few of these limpets of this same coloration on the rocks in the tide pools at this beach. There were others, but they were of different species or had different coloration. This limpet caught my eye because of its odd black stripes. Limpets are a species of sea snail that have very simple, flat shells. They stick themselves to rocks, just like this one in particular was.
I saw several of these limpets nestled among the barnacles attached to the larger rocks at high tide.
The name Limpet is used for many kinds of mostly saltwater but also freshwater snails, specifically those that have a simple shell which is more or less broadly conical in shape, and which is either not coiled, or appears not to be coiled, in the adult snail.
