Great find, and lovely to find it in heart form. It looks to me like a kind of "Sea Wash Ball". They are in fact the empty egg cases of a large marine molluscs. Possibly from the Common Whelk (Buccinum undatum Linnaeus).
@mona65, Thank you Mona, so much for your answer. I am always seeking for latin names or at least names of creatures and plants that I photograph, and it is not always easy when you start with a photo and a local name that doesn't even exist in our own vocabulary....Are you a biologist or something?
