2. Any one of many species of marine shellfish of the order
Docoglossa, mostly found adhering to rocks, between tides.
Note: The common European limpets of the genus {Patella}
(esp. {P. vulgata}) are extensively used as food. The
common New England species is {Acm[ae]a testudinalis}.
Numerous species of limpets occur on the Pacific coast
of America, some of them of large size.
3. Any species of {Siphonaria}, a genus of limpet-shaped
Pulmonifera, living between tides, on rocks.
4. A keyhole limpet. See {Fissurella}.