Cross-section showing vertical zonation on a rocky shore. (1) Lichens; (2) Blue-green Algae; (3) Rock Louse; (4) Periwinkles; (5) Small Acorn Barnacles; (6)Finger Limpets; (7) Rock Crab; (8) Common Acorn Barnacles; (9) Rockweed; (10) Sea Lettuce; (11) Blue Mussels; (12) Purple or Ochre Sea Stars; (13) Aggregate Anemones; (14) Black Chiton; (15) Wrinkled Whelk; (16) Red Sea Urchin; (17) Opalescent Nudibranch; (18) Sun Star; (19) Gian Green Sea Anemone; (20) Brittle Star; (21) Calcareous Tube Worm; (22) Kelp Crab; (23) Red Rock Crab; (24) Orange Sea Cucumber; (25) Bull Kelp; (26) Octopus; (27) Sargassum.