is this a seashell?

[paul monfils]

Well, it comes from the sea, and its "sort of" a shell, but not what we usually mean when we speak of "seashells".  Most "seashells" come from a group of invertebrate animals called "mollusks", which includes snails, clams, cockles, mussels, etc.  This animal belongs to a completely different phylum.  It's a sea urchin, a relative of starfishes, in a phylum of animals called "echinoderms", meaning "spiny skinned".

Here is some more information on these animals: <!-- m --><a class="postlink" href="http://en.wikipedia.org/wiki/Sea_urchin">http://en.wikipedia.org/wiki/Sea_urchin</a><!-- m -->