ID on rock dwelling hitchhiker

[mark-aus]

Hi all, hoping for an ID on this or these things. Hiding in my rock. I had a look through the sticky and nothing except maybe hydroids came to mind. You see it move something out of its hold and it seems to be popping out of multiple points in the rock. These were taken during the middle of the photo period.

Video coming just need to cut it down
Edit: On reflection bristleworm/s?

 

[Rtaylor]

Micro brittlestars, those are its arms sticking out. Good guys

 

[mark-aus]

Micro brittlestars, those are its arms sticking out. Good guys

Hah so it is, thanks!