wild looking shell found in hawaii

[lief]

any ideas? it appears that there was another half, but it's gone now! not the most beautiful picture, but should do the trick...

thanks!

<a href="http://www.badongo.com/pic/9176597" target="_blank"><!-- m --><a class="postlink" href="http://www.badongo.com/pic/9176597">http://www.badongo.com/pic/9176597</a><!-- m --></a>

[paul monfils]

Well, this is a "shell" in the general sense, but it is not from a mollusk.  It is the carapace (upper "shell") of a crab. I'm not in a position to ID crab species.

[sakura-of-the-sea]

It's definitely a type of swimming crab from either the genus <i>Callinectes</i> or <i>Arenaeus</i>.