Black spots on monti cap

[dcforester1]

I dont know if it has been on them, or if its new, but I have a few big spots on the underside of my Monti Cap. I was searching online, and all I see is post with tiny dots. These are pretty big 1/2in across. Anybody got any ideas?
TIA Derek

 

[stingythingy45]

What color cap,Derek?
On that huge orange cap colony I have coralline forms near the base.

 

[dcforester1]

Its purple, it died, but made a comeback. I dont think the spots were on there. It looks like a cigarette burn on the back. Thanks for the help.
Derek

 

[spaceship]

My large cap

on my small caps they have pretty white bottoms but my large orange cap the inner most like 5-6 inches in it looks like live rock under neath with coaline....and some sponge....

 

[dcforester1]

This is a black like a burn mark. I will post a pic tomrrow