Bivalves are mollusks with two shells.
Abalone Jingle
Pododesmus cepio
(1-4: San Carlos Beach, Monterey / 5-6: Monterey State Beach, Monterey)
These are jingles, not abalones, despite the name. They stick flush against rocks, even conforming to the shape of the rock if it's not flat.
Bay Mussel
Mytilus trossulus
(1: San Carlos Beach, Monterey / 2-3: Lovers Point, Monterey)
Lacks the radiating ridges of the California mussel (Mytilus californianus).
California Sunsetclam
Gari californica
(1: Whaler's Cove, Point Lobos)
These live under gravel, so normally you just find the shells.
Geoduck Clam
Panope generosa
(1: Monterey State Beach, Monterey / 2-7: San Carlos Beach, Monterey)
Giant Pacific Scallop
(aka Weathervane Scallop)
Patinopecten caurinus
(1: San Carlos Beach, Monterey)
Heart Cockle
Clinocardium nuttallii
(1: Monterey State Beach, Monterey / 2: Whaler's Cove, Point Lobos)
Mediterranean Mussel
Mytilus galloprovincialis
(1: Bluefish Cove, Point Lobos)
Rock Scallop
Crassedoma gigantea
(1: Monterey State Beach, Monterey / 2,6-8: San Carlos Beach, Monterey / 3-4: Sutil Island, Santa Barbara Island / 5: Flame Reef, Santa Cruz Island)
Scallops have lots of eyes:
(1: San Carlos Beach, Monterey)
Commonly covered in yellow sponge.
Scaleside Piddock
Parapholas californica
(1-2: Whaler's Cove, Point Lobos)
Sea-Bottle Clam
Mytilimeria nuttallii
(1: Monastery Beach, Carmel-by-the-Sea)
Spiny Pricklycockle
Dallocardia quadragenaria
(1: Monterey State Beach, Monterey)
Spiny Scallop
Chlamys hastata
(1,3: San Carlos Beach, Monterey / 2: Whaler's Cove, Point Lobos)
Also frequently covered in yellow sponge.
Wart-Neck Piddock
Chaceia ovoidea
(1: Monterey State Beach, Monterey / 2: Ship Rock, Santa Catalina Island)
