Caliphyllidae (sea-slugs)
Calliodentaliidae (tusk-shells)
Calliostomatidae – Calliostomatinae (conical top-shells)
Calliostomatidae – Thysanodontinae (conical top-shells)
Calyptraeidae (shelf-limpets)
Cancellariidae – Cancellariinae (nutmeg-shells)
Capulidae (cap-shells)
Cardiidae – Laevicardiinae (cockles)
Cardiidae – Protocardiinae (cockles)
Cardiidae – Trachycardiinae (cockles)
Carditidae (false-cockles)
Cavoliniidae – Cavoliniinae (sea-butterflies)
Cavoliniidae – Clioinae (sea-butterflies)
Cavoliniidae – Creseinae (sea-butterflies)
Cerithiidae – Bittiinae (creepers)
Cerithiidae – Cerithiinae (creepers)
Cerithiopsidae – Cerithiopsinae (false-creepers)
Cerithiopsidae – Seilinae (false-creepers)
Chaetodermatidae (aplacophorans)
Chamidae (jewel-boxes)
Chilodontidae (pearly top-shells)
Chiroteuthidae (squid)
Chitonidae – Chitoninae (chitons)
Choriplacidae (chitons)
Chromodorididae (sea-slugs)
Cingulopsidae (false eaton-shells)
Clavagellidae (watering-pots)
Cleidothaeridae (rock-clams)
Cocculinellidae (cap-limpets)
Colloniidae (argalistas)
Colubrariidae (bloodsucker-whelks)
Columbellidae – Atiliinae (dove-shells)
Condylocardiidae – Condylocardiinae (condyl-clams)
Condylocardiidae – Cuninae (condyl-clams)
Conidae – Clathurellinae (false-turrids)
Conidae – Coninae (cones)
Conidae – Daphnellinae (false-turrids)
Conidae – Mangeliinae (false-turrids)
Conidae – Rhaphitominae (false-turrids)
Corbulidae – Corbulinae (basket-shells)
Costellariidae (ribbed-mitres)
Cranchiidae (squid)
Crassatellidae (thickshell-clams)
Cryptoplacidae (fleshy-chitons)
Ctenopterygidae (squid)
Cuspidariidae (spoon-shells)
Cyamiidae (arc-mussels)
Cylichnidae (peanut-shells)
Cypraeidae – Cypraeovulinae (cowries)
Cypraeidae – Gisortiinae (cowries)
Cystiscidae – Cystiscinae (margin-shells)
Cystiscidae – Granulininae (margin-shells)
Cystiscidae – Persiculinae (margin-shells)