Here's a nice picture of an argonaut with shell case.
http://is.dal.ca/~ceph/TCP/Argo.html
By the way, for those interested in Cephalopods, this is a great site.  I found it
as a link on the Jacksonville shell club page.
 
 
Thomas E. Eichhorst wrote:
 
> Nora,
>
> The argonaut shell is indeed an egg case developed by the female
> argonaut.  The males are much smaller than the females and without
> shell.
>
> Tom
>
> NORA BRYAN wrote:
> >
> > Thanks David, I forgot to acknowledge you in my earlier Reply (somehow your
> > reply wasn't connected to the thread).  I thought that the Argonaut shell was
> > an egg case, and therefore solely female.  I need to do some more reading I
> > guess.
> > Nora Bryan
> > Calgary, Alberta
> > Canada