Shells with holes - ID both shell and animal that made them

[paul monfils]

A scattering of small holes over an area is usually caused by boring sponges.  A single hole penetrating all the way through the shell, especially if located near the hinge area, is usually caused by a carnivorous snail of some kind.  Smaller holes with straight sides are produced by oyster drills.  Larger holes with beveled edges are produced by moon snails.  Small holes that lead into winding tunnels in the shell can be produced either by boring worms or by boring bivalve mollusks.  If you can provide a few fairly clear closeup pictures, we can probably give you further information both about the shells and the holes.