I would like to offer a point, each, regarding shells damaged by drilling
and shells damaged by wear, probably not from wave action.  First, my
collection includes only one shell to which I have given a personal name,
and it remains one of my favorites.  I call it "Dumb and Dumber."  It is a
live-taken Pteropurpura with two holes drilled, one into the ventral
aspect, midway along, axially, the callus.  Somehow, it appears to have
missed the critter.  That was "dumb," but dumber was the hole drilled
completely through the wide, flared lip, with no reasonable expectation of
hitting the retracted animal.  Secondly, I have taken two Volutopsius
furukawai (I think) which I got alive although their shells, just
posterior to the aperture, on the ventral aspect, were worn all the way
through, with the animal bulging partly out the irregular wear opening.
The shells are otherwise quite intact and strong, except where worn
through as stated.  Most Volutopsius, including a lot of
middendorffi/emphaticus I get are worn "bald" there, through their perio,
and several hsve been worn quite thin there, some even with slight holes
worn through, but these two are the only ones I found substantially
exposed to attack, in that way.  I am curious to learn on what terrain
they are dragging their shells so abrasively.

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