The wonderful and legendary Argonatuta argo - the egg carrying case of the female Argonaut - a member of the octopus and squid family. Once the shell is made, the eggs are deposited into the shell and they are released onto the sea's surface and are allowed to float away until the eggs hatch. Occasionally the empty shells arrive on distant shores after storms and are rarely found intact and damage free.
A very good overall size of approx 16 cm.