Seanet High/Mid Intertidal

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Tetraclita rubescens Darwin, 1854
Phylum Arthropoda, Subph. Crustacea, Class Thecostraca, Subcl. Cirripedia, Order Thoracica, Family Tetraclitidae

Acorn barnacle, shell plates reddish (white in young uneroded individuals) with a thatched appearance; to 30 mm diameter.  With only 4 shell plates instead of 6 (as in all other local acorn barnacles).

Common, mid- to low intertidal zones on exposed outer coast.

Geo Range: San Francisco to Cabo San Lucas (Baja)
Synonyms: Tetraclita squamosa rubescens
Similar species: Semibalanus cariosus also has a thatched appearance, but is not reddish and has 6 un-equal shell plates rather than just 4.

small limpets are probably Lottia scabra.