Starfish ID please

[Hingeback]

This was in one of my acro's as my lights went on. Anybody have any ideas as to what it is and if harmful.
http://i41.photobucket.com/albums/e261/Hingeback/P2294501.jpg

http://i41.photobucket.com/albums/e261/Hingeback/P2294500.jpg

Thanks.

[Hingeback]

I am thinking it belongs to the Asterina family.