Please Id This Hitchiker

[Mark82]

I was removing this off of my blasto wellsi rock. I thought it was a purple mushroom, yet when I took the rock out of the tank to remove this I found it was hard skeleton with soft tissue...from the top the skeletal structure resembles a umbrella.The coloring is purple with green streaks. It also has little tentacles.Here is a couple pics any help will be appreciated.
Thanks Mark

 

[coral diver]

Ric or Yuma more focusing please

 

[pookstreet]

Ric or Yuma more focusing please

Rics have no skeletons. Kinda hard to tell from the fuzzy pix though.

 

[scallopking]

Maybe a cynaria or scylomia (sp?).

 

[Mark82]

Sorry guys my camera sucks. Do you guys think it could be a short tentacle plate coral? that's what some one suggested. They said the cap will eventually come off the stalk to sit flat on the substrate.