Dear Manuel,

You have convincingly described an (aquatic) Ampulariid snail in the genus
Lanistes Montfort, 1810.  As best I can tell the genus is limited to
Africa.  The animal is actually dextral, which means the left-handed shell
is hyperstrophic pseudosinistral.  Confusing?  Maybe that's why they're
(along with confamilal relatives) called mystery snails?

Harry


At 12:27 AM 7/13/99 +0200, you wrote:
>Dear friends:
>
>        A friend of mine brought me an interesting shell from his trip to
>the Okanvango Delta, in Bostwana. It is sinistral, about 45 mm big, greenish
>in colour, and silky in appearance. It was collected inside the water, so it
>seems to be a fresh water species, rather than a land or tree snail. Do you
>know what species is it? I have no experience nor references for this sort
>of shells.
>        Thank you, and greetings from southern Spain
>
>                                Manuel Jimenez Tenorio

Harry G. Lee
Suite 500
1801 Barrs St.
Jacksonville, Fl. 32204
USA   904-384-6419
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