Anemones? help me ID these guys on TBS Live Rock?

[Giraffe0621]

Are these tiny anemones? EAch about 1/2 cm to 1 cm, looks like tentacles around a central base/mouth? Haven't seen them move, and don't think they look like the aiptasia I've seen (they don't have a stalk -- just tentacles & base). they're clear with sort of white speckling. Hope that makes sense? And yes, there are white/clear stringy looking sponges on here too... looking at pretty much dead center of 1st picture, and a cluster of them in the 2nd picture. Help me out?! Thanks!!

 

[KJ]

Cup Coral.

 

[Giraffe0621]

Cup Coral.

Thanks KJ - you seem to be ID'ing a lot of stuff for me! Is it possible these guys are spreading in my tank even if it's really new? Guess I could be just noticing them more?

 

[ThunderGoose]

I got some of these hitchhiking on live rock. They have gotten bigger and are expanding but not moving around to new spots in the tank. They're a typical coral as far as I can tell.