Identification New Jersey #3

[paul monfils]

Yes, they are all Anomia simplex.  It is quite variable in color and shape. The flat ones with a hole on one edge are the lower valve of the shell. A stalk passes through the hole, to attach the animal to the substrate. The more convex ones without a hole are the upper valve, and are usually much more common on the beach because some of the lower valves remain attached to the substrate after the animal dies.