rock anemone?
 

I think I have a small rock anemone in one of my rocks. I see bands around the tenacles. Are these nuisance anemones? I tried to get a pic., but I have an older camera and you couldn't see it. It is very small.

Without a pic there is not way to id your anemone.

try looking up similar pics of it online and try to identify it that way. Its probably a bad anemone if it came from the rock.