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