- In a general sense, any hatshaped, or conical, gastropod
shell. - Any one of many species of marine shellfish of the order
Docoglossa, mostly found adhering to rocks, between tides. - Any species of Siphonaria, a genus of limpet-shaped
Pulmonifera, living between tides, on rocks. - A keyhole limpet. See Fissurella.