Photo of a "mermaid's purse" on Trefor beach, Wales.
User <a href="https://en.wikipedia.org/wiki/User:Stemonitis" class="extiw" title="en:User:Stemonitis">Stemonitis</a> on <a class="external text" href="https://en.wikipedia.org">en.wikipedia</a>
CC BY-SA 2.5
Taken by <a href="https://en.wikipedia.org/wiki/User:Stemonitis" class="extiw" title="en:User:Stemonitis">Stemonitis</a>.