Can anyone help me identify this shell?

[xylox]

I need to know the Class, order, superfamily and family of this shell. Can anyone help?
<img src="http://i45.tinypic.com/vpdcon.jpg" alt="http://i45.tinypic.com/vpdcon.jpg" style="border:0" />
<img src="http://i49.tinypic.com/2d1mh06.jpg" alt="http://i49.tinypic.com/2d1mh06.jpg" style="border:0" />
<img src="http://i50.tinypic.com/w4r3p.jpg" alt="http://i50.tinypic.com/w4r3p.jpg" style="border:0" />
<img src="http://i46.tinypic.com/66f9.jpg" alt="http://i46.tinypic.com/66f9.jpg" style="border:0" />
<img src="http://i45.tinypic.com/ziq4xf.jpg" alt="http://i45.tinypic.com/ziq4xf.jpg" style="border:0" />
<img src="http://i48.tinypic.com/f2ndzd.jpg" alt="http://i48.tinypic.com/f2ndzd.jpg" style="border:0" />
<img src="http://i48.tinypic.com/2ijgq3r.jpg" alt="http://i48.tinypic.com/2ijgq3r.jpg" style="border:0" />
<img src="http://i50.tinypic.com/2yw6ah4.jpg" alt="http://i50.tinypic.com/2yw6ah4.jpg" style="border:0" />

[paul monfils]

The species is Hexaplex cichoreum.. Here's the requested information:

<a href="http://www.taxonomy.nl/main/classification/36359.htm" target="_blank"><!-- m --><a class="postlink" href="http://www.taxonomy.nl/main/classification/36359.htm">http://www.taxonomy.nl/main/classification/36359.htm</a><!-- m --></a>

.

[xylox]

Thank you for the help