Limpets
Limpets marine Mollusks of the class Gastropoda. They are somewhat like a snail, but have a flatened, cone-shaped shell. They live on rocky coasts of most oceans. Limpets can be commonly found attatched to rocks at low tide, looking like little disks or bumps on the surface of the rock. They create suction with their shell to keep them attatched to the rock and to prevent them from drying out. When the tide returns, they lift their shell and continue to graze on algae.
Sometimes a Limpet Mine is refered to as a Limpet.