Hi Bob,
The genus is not bogus, but it is not molluscan either.  It is a lamp shell
or Brachiopod.  These shells look superficially similar to bivalved molluscs,
but they are not closely related to molluscs at all.  The internal anatomy is
very "un-molluscan".  The hole in the shell, just below the umbos, is where a
thick stalk protruded, anchoring it to the sustrate.  In life, the shell sits
atop the stalk like a golf ball on a tee.
Paul M.