Unidentified fuzzy sacks on my star polyps

I'd appreciate any help you guys can offer:

These things only grow on my star polyps. I can't figure out what they are.
Sometimes there's a few and sometimes there are several. I seem to have a
lot of them now. When the polyps are open these things are totally hidden.
The star polyps seem very healthy. All water tests are perfect.

Each on has an opening at the top. I never see anything go in and out so it
must be for nutrition... awww, I don't know.

A pic is worth a thousand words so go take a look.

Got some pics he
http://www.geocities.com/bryg30/Unkn...tarPolyps.html


For my tank set up: www.geocities.com/bryg30

Thanks again. Feel free to ask me questions of course.

Bryan