Thanks for the help. The pic was taken with my cell phone and is pretty poor. I'll try to post another if I can get a better shot of it.
I acquired it about 7 years ago when it was about 3" in diameter. It's now about 7".
I can tell you, it's tough. I lost power, during the summer about 5 years ago, and it was one of the few corals that survived. It was off for a couple of days and the indoor temps reached 90 to 100 with no AC.
It's really starting to develop into a "show piece" that seems to draw your attention when you first look at the aquarium.
I have a rotating powerhead that sweeps a flow of current across it to keep it free of any detritus that might try to accumulate in it's "cup". That's really the only special attention it gets.