Aloha Ross,
In Hawaii i've found seemingly GEM quality Conus spiceri. After removal of
the periostracum often they're numerous small boring produced cavities made
by microscopic bivalves doting the apex & ventral surfaces. The dark
staining in the cavities are evident of the habitat. Very fine dark muddy
sand. In the Philippines this is evident w/Conus virgo. The same numerous
micro-drilled holes are present where the Conus makes contact to the
substrate.

I've never seen internal boring in reef occuring species, only sand dwelling
species. Larger species such as leopardus have larger bore holes and are
less numerous. Many virgo have "doctored" apex where the holes have been
filled w/calcium-based bondo used in repairing teeth. Hope this helps. CT