I might have to disagree. I think that the "big" one is a Cinarena, or Modern, coral. It kinda looks like a bubble but doesn't have the actual bubbles and does have a conspicuous mouth. At least, that's my opinion.
Originally posted by RyeBread
The coral in the middle is Scolymia sp. Or " Donut Coral ".
I couldn't agree more Another name for it is the "tooth coral."
Graham