Dear Ross,
 
there are other samples of two exact nearly identic species from
Fam. Rissoidae living in the Mediterranean. Maybe only distinguish-
able from the Protoconch. And if you have the best microscop of
the world
 
Alvania cimex (Linnaeus, 1758)
Alvania mamillata Risso, 1826
 
Who is classifying these shells without a good microscop can
think about the to its distribution and localities in the Mediterranean.
Good luck for classifying these shells.
 
There might be some other samples if you find in the detritus
only dead shells and some with not a good apex.
 
Send them to some experts, there are also some opinions.
 
What do you think. Please let me know
 
yours Helmut
 
----------
> Ross:
>
> In Cypraea there are several groups of species that are not possible for
> people I know to separate:  The C. rashleighana group eg C. burgessi
> differ from others only by mantle characteristics and/or radulae.  In
> the C. carneola group two differ by mantle papillae and by a ring around
> the shell which fades quickly and isn't present on all shells so they
> can't be separated unless fresh shells are involved.  In Bursidae, I
> found two species that have different opercula, which would make them
> different species.
>
> Aloha,
>
> Wes
>