Round white masses - don't know what they are!

I could use some help with these critters... They are mostly round white masses, they appear to be segmented (Think of the panels on a soccer ball) and they actually move! thin tendrils will attach to nearby spaces on the LR and the next day - new location! I have quite a few of them. Thanx! ( sorry about the blurry pic, tried to zoom in for a better look)

 

i have those too, i'd like an answer as well!!!!

 

Looks like a sponge to me, I have similar loking sponges in my tank. Not so sure about the moving location thing though, mine occasionally move but very very slowly.

 

Looks like a similar spp. to Tethya aurantium

Réserve Naturelle Marine de Cerbère - Banyuls

 

AKA the golf ball sponge

 

Thanks for the info! Its nice to be able to tell folks something besides "I dunno!"

 

possible pineapple sponge---harmless