Lindsey Groves,
 
Thank you very much for the information regarding Cypraea mus and Cyp. stercoraria
...
 
I was aware of the separate genus designation of these species but I had no
information about the fossil records of their early appearances and not much to go
on as far as investigations on the "soft parts".  In fact, the general reference
books: Joyce Allen's book on Cowries, and "Burgess' Cowries of the World" (I only
have the first two editions of Burgess) did not seem to indicate that animal studies
on these species were done or  they were unavailable for comparison when these books
were being prepared.
 
My recent interest on the status of the two genera Barycypraea and Trona was
prompted by the thought that by now new information might be available and some
interesting insights might be revealed.  I am satisfied to hear that radular and
anatomical differences are observed between Muracypraea mus and Barycypraea
teulerei.  Now, I wonder what radular and anatomical differences there are between
Muracypraea and Trona, and also veliger stage (present or absent) in each.
 
Unfortunately, the Burgess books did not cite subfamily, genus, and subgenus
designations, and the Joyce book is way out of date on that kind of information so I
was working with old news at best.
 
> Trona stercoraria is in another subfamily altogether: namely Cypraeinae, a much
> younger group paleontologically as well.
 
Yes, even conchologically speaking the species seems well equipped with the more
recent developments.
 
>  So the lineage that mus is a part of was
> established long before the stercoraria lineage and are therefore, certainly
> related but distantly.  See fig. 53 (p. 29) of Lorenz & Hubert (1993) "A
> hypothetical family tree of cowries" for an overview.
 
I will be interested to get the Lorenz & Hubert books to update my reference
library.
 
Many thanks for your time to bring me up to date.
 
Respectfully yours,
 
Michael LaFosse