What is this?

[spookyspook]

So, I bought a small peice of live rock and it has a few aiptasia/manjo anemones on it, those I know I need to kill. BUT, on the other side of the rock is this weird hole/tube. It sorta looks like a coral skeleton being round with ridges goin from the inside out sorta like a sun with rays. And when I turned the lights out these short clear tentecles with white tips came out. What is this?

 

[spanko]

Pseudocorynactis sp.
Like this?

 

[spookyspook]

Eh, the tentecles look right but, I'm not sure about the mouth. I can't really see a mouth at all. It's just a ball of these legs coming out of a tube that I thought was a coral skeleton