wierd stuff on my rock

[donk18]

okay i don't know how explain this but i will do my best. i can't get a good picture of it. it is white, stringy and looks kinda like a bunch of small brains. it is growing on two of my rocks but i have no clue what to think of it.

 

[Grins]

Maybe a structured sponge?

 

[JunpoweR]

Pics??

 

[Blossom112]

i have the same thing i think ......... grins is probably right
here is my fav link she gave me
http://www.xtalworld.com/Aquarium/hitchfaq.htm