Nora,
The cowrie polishing can be a natural event as well as man-made.  I've
picked up many wave-worn, purple dorsumed cowries on beaches over the
years.  I don't know for sure, but some of these were probably named by
early workers.  Perhaps some enlightened cowrie collector/investigator
knows whether this naming error was ever made and on what species. ????
 
 
 
 
At 10:49 AM 2/8/99 -0700, you wrote:
>Nora,
>
>You are correct, both shells have been polished.  Many cowries will show a
>purple dorsum when the outer layer is polished away.  The most commonly seen
>are purple Cypraea caputserpentis and C. moneta -- I know them well as I
>have examples of both that I purchased back in my younger days.  But as for
>throwing them out, that is not really necessary as they can make an
>interesting display next to a shell in the original condition.  I have the
>African turban (Turbo sarmaticus), button top (Tectus niloticus), and west
>Indian top (Cittarium pica) all with both polished and unpolished specimens.
>It makes an interesting display.  People who know little about shells like
>the polished specimens, of course.
>
>But it is in fact all a matter of degree.  This last year I saw specimens of
>Conus striatus that had been polished for sale at a store in California.  I
>had never seen a polished cone and at the time could only think about what a
>waste as some looked like pretty nice shells.  Now I kind of wished I had
>picked one up as another example of a polished shell.  An interesting
>display could start with a C. striatus with the periostracum, then one after
>cleaning in bleach, then one with a "dressed up" lip, then a polished
>specimen; from scientific specimen to collector specimen to square filler
>specimen to tourist specimen.  Just a thought.
>
>Tom Eichhorst in New Mexico, USA
>