Brown blob in overflow?

So a few days ago I was prodding around my tank looking for something and I looked in the overflow....and I see this big brown blob. I have no idea how long it's been there and I cannot ID it.

It's brownish green, a bit under 2" across at the widest. It has a tough slimy skin that feels thick, but it's not solid... like there's jelly inside. It's on the inner baffle wall of a built in over flow... it's not completely submerged, but it's always wet.

My best guess is that it may be some kind of kelp holdfast maybe?



A much larger (4mb) image can be found here: http://www.greymatter.org/fish/ids/DSC_0455.JPG


thanks!

 

May be brown bubble algae.

 

Should I get to work defining a new species?

 

Ugh! That is nasty lookin'!!