Mystery Blob ID

So I recently lost my puffer. So now I just have 3 fish and the eel...

And there's a half dollar sized white blob that the fish are picking at. I never had a snail that size (it's bigger than a half dollar). I was babysitting a really sick anemone but those guys just melt into nothingness upon death.

All corals are accounted for.

It looks like a large scallop (the kind you eat) if it had been soaking in water and picked at a lot. There's no clams in the tank..

Any clues? This is really bugging me!
 
Unfortunately the bluetooth sync between my phone and computer requires more numbers than I can put in my phone.

It really looks like a boneless fish that's been dead for a while. But all fish are accounted for..

Maybe the 'nem wasn't dead yet and the wrasse and damsel were poking at it? It's completely white, no color in it at all. This is really tripping me out!
 
It's the exact same color as the sand so my phone isn't picking it up.

I'll just deal with never knowing what in the heck it was. It's too big to be the pistol shrimp's remains... and all fish are accounted for. There's nothing on the top glass that could have fallen in either.
 
Top