urchin identification

[fittiger]

I recently found what I am assuming to be and urchin in my tank. Is there anyone who can identify it for me and let me know if its harmful in any way.

Thanks,
Dustin

 

[racrumrine]

If you can't take a picture to show us, try looking here http://melevsreef.com/id/clams.html

Best of luck,

Roy