Slipper Limpet
Crepidula fornicata
Shell length 30mm

Accidentally introduced from N America and now widespread around coasts of S and E England and S Wales. Shell ear-shaped and greyish. Sometimes found in large enough numbers for empty shells to dominate debris on beaches. In life, attaches itself to mussels, oysters or other slipper limpets. Favours sheltered coasts.