The protoconch in the family of Rissoidae is very important for classifying the species. There are
very similar different species or made by human beings, as Alvania cimex and Alvania mamillata.
and others, Rissoa lia, guerinii, similis, eg.
But you always can't see the protos under the microscope very well.
with best shelling greetings
Helmut

Helmut "Helix" Nisters
Franz-Fischer-Str. 46
A-6020 Innsbruck / Austria / Europe
phone: 0043 / 512 / 57 32 14
e-mail: [log in to unmask]
web:    www.netwing.at/nisters/
           (please visit it and sign guestbook)
always looking for shellgrit from all over the world
for my nearly 89 years aged mother Irmgard
to makes happy and to keep up her health

office:
Natural History Department of the
Tiroler Landesmuseum Ferdinandeum Innsbruck
Feldstrasse 11 a
A-6020 Innsbruck / Austria / Europe
phone: 0043 / 512 / 58 72 86 - 37
web: www.tiroler-landesmuseum.at
        (specimen donations to the
         Tiroler Landesmuseum molluscs collection
         are always appreciated)

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-----Oorspronkelijk bericht-----
Van: Andrew Dickson [mailto:[log in to unmask]]
Verzonden: vrijdag 16 juni 2000 05:54
Aan: [log in to unmask]
Onderwerp: Re: Protoconchs


Dear Conchlers,

I would like some educated comments about how important protoconchs are
for the identification and/or separation of similar species.  It seems to
be easy for some collectors to accept the use of protoconchs for the
separation of certain species.  When it comes to some of those more
controversial shells, protoconch differences can or tend to be ignored.

Busycon sinistrum pulleyi is a shell with a different protoconch but
there are not many who think it is different species.  On the other hand,
there species of Maurea from New Zealand which are very similar and
separated by the protoconchs.

I seem to sense protoconchs may not be a great indicator for separation
of species in general.  Perhaps they may only show evidence of a
subspecies.

I hope to see some of you at the C.O.A.

Andrew Dickson

In some cases Protoconchs are extremely usefull. In western Europe, fossil
species of the genus Streptodictyon [Fasciolariidae] can hardly be
identificated when the protoconch is missing. This is a problem because the
holotypes of the species are adult specimens, without protoconch!
In the Turridae the protoconch is very important for identification. The
protoconch is also used in the identification of Pteropods. In publications
about Voluta's I saw a  enormous diversituy in the protoconchs.
So in my opinion the protoconch is important for the indentification in
quite a lot of gastropods families.
Martin C. Cadee, The Netherlands