Clam species mostlikely in genus Katelysia

In Australia We call them pipi shellfish , The name pipi comes from the Maori people of New Zealand.
Many of the shells I found had a hole in it which are made by moon snails who prey on the pipies in drilling a hole into the shell and then injecting a chemical which dissolves the mollusk ,enabling the moon snail to suck the liquified molusc out of its shell with a long protruding tongue.