mundum is very common (I have 6 of them from various intertidal localities,
including Tuamotus), but half of those were misidentified as gemmatum by
three different dealers.

I have only one gemmatum, a gift from Ranellidae expert Betty Jean Piech,
and it is very different: more slender, lighter, with more prominent and
regular axial sculpture, longer and thinner anterior canal, tan color
overall (mundum is white with a very light brown periostracum). It came
from P.I. tangle nets. About the only thing the two species have in common
is the overall length (44mm WRS for gemmatum, 50 for mundum)

John

At 10:20 PM 9/25/2005, you wrote:

>Does Cymatium gemmatum occur in the Tuamotus, French Polynesia?  Hemming
>& Hennen indicate a Western Pacific range; but Coquillages de Polynesie
>includes a shell it calls gemmatum.  Are shells labeled as being
>gemmatum from French Polynesia actually misidentified mundum?
>
>It seems there has been much confusion and contradiction in the
>literature regarding gemmatum and mundum, which some authors considered
>synonyms.
>
>Descriptions of gemmatum say it is tan or brown.  Some of the pictured
>"gemmatum" on the web are pure white.  Are those actually mundum, or are
>white gemmatum a common variation?
>--
>Cecil N. Bankston
>Baton Rouge, LA
>USA

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