- Norwegian: albuesnegler
A typical limpet has a flattened, conical shell and sits on a hard surface, like a stone or a ship hull. The shall has no windings. The limpets can be hard to spot as they are often covered in growth. The largest limpet, Patella mexicana may reach a diameter of 20 cm, but most species are less than 8 cm.
The limpets are well adapted to a life in the intertidal zone, due to their ability to maintain humidity under the shell during hours of low tide.
The former subclass Prosobranchia that included all gastropods with the heart positioned in front of the gills, is no longer valid. It is replaced by three subclasses, where the limpets constitute one, Patellogastropoda. This subclass includes only two superfamilies in the European marine fauna, Lottioidea and Patelloidea.