While I was on Sapelo Island, I learned quite a bit about the fauna living in the surf zone and just off the coast by beachcombing. Snail and clam shells, crab carapaces, parchment worm tubes, sea whips and jellyfish are among the interesting finds in the litter washed up on the shore.
A useful pictorial guide to mollusk shells and other animals that can be found on Southeastern U.S. Atlantic beaches is posted at:
The photo above shows shells of a delicate white channeled whelk, and a robust knobbed whelk, two common snails that live just off the beach.
These lovely lettered olive shells in the photo above belong to a snail that is a deadly predator of bivalves living in the surf zone Olive snails feed at night, burrowing through the sand in search of small smooth-shelled clams that they kill by smothering them with their muscular foot.
Another common shell found on the beach is that of the moon snail, or shark's eye. The white mantle of the live snail is so large that it cannot be completely contracted into the shell, but instead serves as a lubricated plow that the snail uses to burrow through the moist sand of the lower beach.