What kind of shell is this one?

[bluenite]

Please help with identification of this shell. I don t have better image, hope it is real one, not two shells together.
Anyway, knows anybody the name?

<a href="http://www.badongo.com/pic/521546" target="_blank"><!-- m --><a class="postlink" href="http://www.badongo.com/pic/521546">http://www.badongo.com/pic/521546</a><!-- m --></a>

Great site, I have looked for one as this.
Thx for reply
Peter