Victoss link said:Pavona coral?
CanadaCorals.com link said:Looks like a lithophyllon \"litho coral\" to me.
Reef Hero link said:I don't think it is a lithophyllon species....
But would like a better pic of tentacles and the corallites. Also, i read that the tentacles on litho are retracted when lights on but come out after dark. Also, lithophyllon is quite rare to see in the hobby....