I never find many shells on the scrap of beach at the bottom of Penarth cliffs, though it’s a good place for dollops of seaglass and the very occasional fossil but, if I do manage to find any shells, they’re usually limpets, probably Common limpets (Patella vulgata).
Things I didn’t know about limpets until just now:
— they can live to the ripe old age of 16
— they are herbivores, feeding on the exceedingly tiny algae that cover the seaside rocks
— they have a tongue with teeth that are so sharp they can scrape the algae off the rocks like a file
— the ‘glue’ they use to attach their single foot to the rocks is so strong it can withstand a force of 75lbs per square inch
— well-fed less-stressed limpets produce flatter shells, whereas hungry limpets produce more dome-shaped shells, so the former inhabitant of the peachy coloured shell I picked up may well have died hungry!