The false pacific jingle shell, or rock oyster, often comes ashore on Taylor Beach attached to the holdfasts of kelp.
Various species of kelp have attached their holdfasts to this rock oyster shell, leading to it being detached and carried ashore on Taylor Beach.
One of the valves of Pododesmus sp.
Pododesmus (Monia) macroschisma (Deshayes, 1839)
Reference: Peter’s seashells