If you’ve ever walked along a shingle beach, you’ll know they can be challenging on the ankles and the leg muscles so I only ventured on to the beaches at Eastbourne and Rye Harbour once at each place. When I did, I noticed an abundance of these shells, which seem to be Slipper limpets (Crepidula fornicata). They are gastropod molluscs, and they are an odd shape with, what The Marine Life Information Network website describes as a ‘large aperture [that] has a shelf, or septum, extending half its length’. They also have an odd method of cohabitation: ‘Slipper limpets are commonly found in curved chains of up to 12 animals. Large shells are found at the bottom of the chain, with the shells becoming progressively smaller towards the top.’ Check out the website for an illustration of this, and for more information about these fascinating sea creatures.