Possibly a Flower Pot?

[paragrouper]

This looks alot like the blushing star (Stephanocoenia intersepts) I received as a hitchhiker on live rock I purchased from TBS.

 

[Reefkeepers Archive]

Corallites too large and polyps too extended to be Porites. I would still say it's a Potitid of some sort, either Goniopora or Bernardpora depending on how the polyps look.

Though @i cant think did mention that he could count around 11 arms on each polyp, and I don't think that's an Alveopora