Limpet

Limpet is a common name for a number of different groups of sea snails and freshwater snails (aquatic gastropod mollusks). The common name is applied to those snails that have a simple shell which is broadly conical in shape, and either is not spirally coiled, or appears not to be coiled in the adult snail. In other words the shell of all limpets is shaped more or less like that of most true limpets.