Judging from your picture, the alternating patterns, banding widths, beading
and peak to diameter shell proportions would lead me to think it is
Perotrochus hirasei, provided it also has a short slit (e.g., 2.5 cm for an
9 cm shell).

It looks very closely like the P. hirasei specimen we have on hand
<http://nighthawk.tricity.wsu.edu/museum/ArcherdShellCollection/gastropoda/P
leurotomariidae.html>

-Burton

> From: Automatic digest processor <[log in to unmask]>
> Reply-To: Conchologists of America List <[log in to unmask]>
> Date: Tue, 7 May 2002 18:34:22 -0400
> To: Recipients of CONCH-L digests <[log in to unmask]>
> Subject: CONCH-L Digest - 6 May 2002 to 7 May 2002 - Special issue (#2002-129)
>
> From: "Monfils, Paul" <[log in to unmask]>
> Date: Tue, 7 May 2002 10:54:02 -0400
> Subject: Slit Shell ID
>
> Hello folks,
>
> Can someone give me a positive ID on the slit shell in this picture?  I
> don't have the shell, or any information about it - just the picture, which
> is not taken from an ideal perspective.  Still, I would appreciate any
> feedback.
>
> Regards,m,
> Paul M.
>
> Here's the picture:  http://members.aol.com/paulcyp/SLITSHELL.JPG