I've been to Carmel occasionally since the early 1950's, and always looked for shells. By far the best place is a tiny cove between main beach and Stillwater Cove. Most visits you can--with diligence--find a few 'Coffee Beans'. Never have I seen them elsewhere. I've always assumed that these were some kind of cowry...
Species from Western North America
Common name: Seep Monkeyflower, Annual Monkeyflower
Photographed along Pine Mountain Fire Road, Marin Municipal Watershed District, Marin County, California