Help Me ID Another Coral... Please

[ReefGeezer]

I did it again. I purchased another tiny piece of unknown coral from my LFS. It was small and mounted to a frag plug. I thought it was a Monti but now that it has grown, I don't know what it is. It stays pretty much oval, its ridges get deeper as it grows in diameter, and it has small sweeper tentacles that come out when there is food in the water. Could it be a plate coral of some sort?

that was mistakenly mounted on a frag plug?

 

[Tahoe61]

Plating Hydnophora, an aggressive coral, give it a wide berth. Sweeper tenticals can reach 5 inches or more.
Mod flow, and light, feed and the coral will grow quickly.

 

[ReefGeezer]

Thanks. It is growing very fast. It went from less than 1/2 dollar sized to over 3" across in a few months. It's down pretty low now, but It's in prime SPS real estate. I think I'll move it to the bottom. Explains why an Orange Cap Monti near it had some random tissue damage. I was blaming a big Urchin, and sent it back to the LFS. Oops.