Hi Dawn,
 
I was the one who mentioned the nickel mines. But what you tell us about
the only Cowries found on Tryon Island being albinistic C. cribraria
confuses me, since I have several Cypraea felina from that locality which
are melanistic and slightly rostrate. And I know of some others, I think.
I'll check tomorrow in a friend's collection. In any event, is this another
case of getting a misleading locality like Emilio Power was talking about
for Cypraea eludens the other day?
 
Also, are the albinistic Cypraea cribraria you mentioned the variety called
Cypraea cribraria melwardi? I've seen some completely white specimens of
those. If I hadn't seen others collected in the same area with vestiges of
cribraria markings on them, I'd hardly believe they were C. cribraria.  And
do they come from elsewhere besides Tryon Island?  Interesting. And where
else  (or where) are the Queensland melanistics you mention from?
 
Best wishes,
 
Lynn Scheu
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>Hi Nora,
>Answer to your question re nickel mines there are large smelting plants on
>the coast of Townsville Queensland but no record of any melanistic or
>rostrations occuring in any shells from that area, also there are no mines
>or smelters in the area where the Queensland melanistics are found.The
>cypraea found on Tryon Island are albinistic cribraria.
>Cheers Dawn
>
>