Mushroom?????
 

I found these little guys on a piece of live rock. they seam to like it a little darker. They are white in color and about a 1/8th and inch around. They are disc like with little tentacles around the rim. - reminds me of a button polyp- Sorry about the bad photos they are in a hard to reach area with my 100mm macro lens (its to big to fit in there nice). Thanks for help with an ID!

[IMG]http://i141.photobucket.com/albums/r77/jacksonimaging/IMG_5064.jpg[/IMG]

[IMG]http://i141.photobucket.com/albums/r77/jacksonimaging/IMG_5063.jpg[/IMG]

The one on the bottom right on the last picture looks like a bleached out mushroom but the others are hard to tell. They could be bleached out button polyps too. I found some of my button polyps that broke off the main colony and fell into the back of the tank. They looked white and kinda deformed, similar to your pictures. Hard to tell.

they look like bleached button polyps