Clams

As I've said, this must be the season for many shells of the same kind to wash on shore. There are piles of these clams - I've always called them Razor Clams, but they may be Jack-Knife Clams. They are almost transparent. Clams are bivalves with both a front and back shell which hinge together. They have a foot which sticks out between the two shells and is used for burrowing into the sand and/or mud and for scooting sideways. They have 2 tube-like siphons on the opposite end which protrude. The siphons go to the surface and take in water full of planktons to "eat" and oxygen for its gills which are located by the foot.
These clams prefer to stay beneath the sand or mud, but can be uncovered by rough surf where starfish, snails, and crabs encounter a feast.
This picture is not large enough for you to see all of the other shells in and around these clams, but there are baby whelks, cockles, and coquina along with other various and sundry shells.