I really don´t know . Help please

[luigi_67]

This shell i founded beachcombing in yucatan , gulf of mexico.
size 30 mm

<a href="http://img401.imageshack.us/my.php?image=dsc02835gb2.jpg" target="_blank"><img src="http://img401.imageshack.us/img401/3151/dsc02835gb2.th.jpg" alt="http://img401.imageshack.us/img401/3151/dsc02835gb2.th.jpg" style="border:0" /></a>
<a href="http://img401.imageshack.us/my.php?image=dsc02840zy2.jpg" target="_blank"><img src="http://img401.imageshack.us/img401/2539/dsc02840zy2.th.jpg" alt="http://img401.imageshack.us/img401/2539/dsc02840zy2.th.jpg" style="border:0" /></a>
<a href="http://img401.imageshack.us/my.php?image=dsc02837ll2.jpg" target="_blank"><img src="http://img401.imageshack.us/img401/7561/dsc02837ll2.th.jpg" alt="http://img401.imageshack.us/img401/7561/dsc02837ll2.th.jpg" style="border:0" /></a>

thanks