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.