Is this a sponge?

[armyman16]

Is this yellow stuff on my live rock a sponge, if not what is it?
It started as a tiny spot and now has spread all over the rock and bigger spots

 

[crister13]

Pix???? That'll help a lot.

 

[armyman16]

Oops my bad

 

[armyman16]

Anybody know?

 

[Flreefer]

Almost looks like green Montipora, with the white edge, but it looks yellowish. Yellow could be from prolonged light deprivation though. It looks like it has little polyps on it. Is it hard or soft?

 

[armyman16]

It's kinda hard, its also spreading and getting darker!

 

[Flreefer]

Could be Monii, but could be a type of corraline algae

 

[armyman16]

Yeah maybe coralline algae! That's what it feels like, and I'm getting alot of it all over my glass