- callum
- captaculae
- cardinal area
- cardinal teeth
- cartilage
- caruncle
- caryophyllidia
- cephalic disc
- cephalic lappet
- cephalic tentacle
- ceras
- chondrophore
- chromatophores
- clavate
- cleioproct
- cloaca
- club
- cnidosac
- coeloconoid
- columella
- columellar lip
- columellar muscle
- columellar tooth
- concentric
- condyle
- convolute
- coriaceous
- costa
- costella
- crenulate
- cruciform muscle scars
- ctenidium
- cyrtoconoid