Just a sponge?

[jeffchapok]

I'm pretty sure this is just a sponge, but it's unlike any others that I have, so I thought I'd post here for confirmation.

 

[Daddy-o]

yup

 

[jeffchapok]

Cool, thanks. I wish they all looked like that. My others all look like this, and I'm getting quite a few of them. Fortunately they are mostly in the shadows on the underside of rocks.