>I have specimens from both the Philippines (very thin, the "standard" Tibia
>martinii) and from the South China Sea (very thick and heavy, like T.
>curta).  The two are quite different and I had planned on one day doing an
>article on them.  In the mean time, here are some measurements taken of the
>two shells that highlight just how different they are.
>
>South China Sea (deep water)
>151mm total length
>3mm outer lip thickness
>1.5mm thickness inside lip
>34.5 grams total weight
>No white subsutural band
>Weak purple banding
>Seven outer lip digits
>Moderately deep spiral cording
>Unevenly tapered teleoconch
>
>Philippines (deep water)
>116mm total length
>1mm outer lip thickness
>.05mm thickness inside lip
>7.2 grams total weight
>White subsutural band
>Strong purple banding
>Five outer lip digits
>Shallow spiral cording
>Evenly tapered teleoconch
>
>As you can see, the South China Sea specimen is almost five times as heavy
>as the Philippine shell and has a much thicker shell.  The Philippine shell
>is extremely thin and feels almost like a common garden snail, Helix aspersa
>(or whatever the most recent name is).  I also have comparison photographs
>if anyone is really interested.
>
>Tom Eichhorst in New Mexico where it is snowing tonight.

This sounds very much as though they were two species. How consistent
are the differences? Comments, Gijs?

How do I go about obtaining one of the heavy shells?
--
Andrew Grebneff
Dunedin
New Zealand
Fossil preparator
<[log in to unmask]>
Seashell, Macintosh, VW/Toyota van nut

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