I'm answering based on the 3rd edition of the International Code of
Zoological Nomenclature. The 4th was published this month and takes effect
in 2000, but I doubt that it will affect the following.

>What is the status of the "Addition material studied"? Is this considered
type
>material.?

When you name a new species, if you list "holotype", "paratypes" and
"additional material studied" the additional material is excluded from the
type series. In our collection it would have the status of "voucher material."

>When revisers of a type lot find that there are more than one species, is it
>permitted to change any of the original labels in a collection?
>Should any new labels or notes, signed by the revisers be added to the
original collection?

You should not write on the original labels, but you can add new, signed,
dated labels stating your findings. You can segregate the different
specimens in different vials to make it clear which specimens your labels
apply to. (In our collection these labels are called "annotations" and have
a particular format; ask the curator or collection manager to find out the
policies of a particular collection).

>If the additional material includes anatomical parts of the mollusc, eg.
>Radula, stylet etc. is it compulsory to deposit samples of this material with
>the new types?

No, but it is preferable.

>Are there any new regulations concerning electrophorensic results of material
>studied when published as evidence with a new species description or as
>distinction between two very similar species? In the latter case what should
>the type material consist of?

Specimens from the same population collected at the same time as those
studied genetically should be deposited as voucher material. Some museums
maintain collections of frozen tissue, so it should be possible to deposit
specimens that later workers can study using the same techniques if it
become necessary to confirm your results. If possible the holotype and
paratypes should be specimens whose identity was confirmed genetically.
This can be difficult with small snails, which are usually crushed whole to
obtain tissue for such studies. If you are working from live material, it
is sometimes possible to relax the individuals so that some tissue can be
clipped for study without destroying the shell. It might also be possible
to extract the animal by making a small hole in the shell and severing the
columellar muscle.

Gary

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Gary Rosenberg, Ph.D.                     [log in to unmask]
Malacology & Invertebrate Paleontology    gopher://erato.acnatsci.org
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