LIMPET

European limpets (Patella vulgata) with acorn barnacles (Balanus balanoides) any of various snails having a flattened shell. Limpets belonging to the subclass Prosobranchia (class Gastropoda) are marine; most cling to rocks near shore. A common American species is the Atlantic plate limpet (species Acmaea testudinalis) of cold waters; the common species of Britain and northern Europe is Patella vulgata. Keyhole limpets, of the prosobranch family Fissurellidae, have a slit or hole at the apex of the shell. Limpets belonging to the subclass Pulmonata live in brackish and fresh water. For slipper limpet, see slipper shell.