Dear All,
there is a problem about " glabella & sebastiani complex " ( Marginellidae
): Marginella pseudosebastiani Mattavelli 1995, probably a new species.
Morphology of this conch now is clear, but biology of pseudosebastiani
remains unknown.
In my opinion the new species exists, but only unofficially. It has never
been published, but since 1995 I have contacted about thirty malacologists.
Among those interested and firm, about half agrees.
Certainly there is a great mess sometimes even in the most known
literature.
Actually in the Compendium of T. Abbott there is not a photo of typical
Marginella sebastiani Marche-Marchad & Rosso 1979. The photo of  Marginella
sebastiani in the Compendium p. 233 is ambiguous, certainly not typical,
maybe very atypical.
For typical sebastiani see Bollettino Malacologico UMI 1979, with original
description of Marche-Marchad & Rosso.
Shortly the real typical sebastiani has very big white spots ( similar to
spots of Marginella goodalli Sowerby 1825: p. 232 Compendium photo of
goodalli is correct, only a bit yellowish ) and seldom it has also the
axial subsutural flames. On the contrary the flames are always present in
the true pseudosebastiani Mattavelli form, or better species, and
pseudosebastiani  always has small white dots. I believe that Marginella
pseudosebastiani is synonym of Marginella glabella atlantidis Carlos Buey
Suarez form, 1980 ( La Conchiglia magazine, settembre/ottobre 1980, n°
138/139 ), but then  Buey Suarez did not give specific value to the form,
while I recognize it as a true biological species.
The photo of p.233 of the Compendium, having small white dots and having
axial subsutural flames, may really be that of a nearly typical Marginella
pseudosebastiani.
Also as to Marginella desjardini Marche-Marchad 1957 the Compendium of T.
Abbott is misleading.
The picture of Marginella desjardini in the Compendium p. 231 surely is not
desjardini, nor atypical.
Actually it could be that of a not typical form of  Marginella
pseudosebastiani, or a hybrid, to define.
For true typical desjardini see  Encyclopedia of Shells of Kenneth R. Wye,
p.205, or see Seashells of the World of Jerome Eisenberg, plate 108, photo
n°20.
In Eisenberg, plate 109, photo n°1 ( wrongly called M. goodalli ) is really
Marginella sebastiani , nearly typical form.
In Eisenberg, plate 108,  photo n°20A ( called M. sebastiani ) is really,
in my opinion, typical Marginella pseudosebastiani.
What do you think of ?
As to M. glabella Linneus 1758, the variability is very wide, it may be
confused with M. irrorata Menke 1828, but I will speak about that sometimes
else. Regards.
Flavio Mattavelli
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