Since no one else has jumped in, let me add 2 cents worth based on
the Iconography and/or Patrice Bail's opinions:

ostenfeldi is a subspecies of larochei (from SW New Zealand)
depressa and swainsoni are synonyms (forms) of arabica
calva is a synonym (form) of jaculoides

John
Lancaster, PA

At 01:19 AM 9/23/2008, you wrote:
>I believe that Alcithoe ostenfeldi is a valid species.
>
>A couple of synonyms of the variable Alcithoe arabica are
>unfortunately still in circulation, depressa and swainsoni. These
>names are NOT valid. There are no "forms" of A. arabica; the species
>is extremely variable, even within a single population; the shell can
>lack any nodes at all, or have any degree of development up to quite
>large shoulder spines and spire-height also varies. Color varies from
>white to flesh and usually has some brown zigzags, but these can be
>very weak or absent. Columellar plaits vary in number from about 4 to
>over 7. The species goes back to the middle Pliocene and some of the
>many named fossil "species" may really be synonyms. Southern
>specimens can reach well over 20cm, possibly to 28cm in length.
>
>A. calva is apparently a valid species, not a synonym of A. arabica;
>the differences in shell characters, I am told, are subtle (mainly in
>the depth of the siphonal notch).
>
>--
>Andrew Grebneff
>Dunedin, New Zealand
>Fossil preparator
>Mollusc, Toyota & VW van nut
>Temporarily in Calgary, AB, Canada

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