I found one of these in the Keys.  The lip was quite thick and displayed "crack"
marks.  I assumed it was an old shell and that this was an extreme case of the
dark greying discoloration common in old Strombs.
 
Marlo
Florida
 
David Hurst wrote:
 
> Hello all,
>
> I have a question that someone may answer for me. I found a live Strombus
> ranius about 3 years ago live in Key Biscayne, FL that had a solid black
> underside. It was found along side the traditional color form seen illustrated
> in books. I was wondering what would cause this color form.
>
>                                                                 Thanks
>                                                                 David