ID question

[Rascal]

Shell on 2/17/06:

 

 

2 days later:

 

 

Under all lights:

 

 

I also found them in a couple of other spots around the tank. As of this morning, they are still there.

 

I have the usual assortment of snails (marharita, nassarius, nerite, cerith), but these don't look like any of those.

 

Any ideas?

Edited February 28, 2007 by Rascal

[Sugar Magnolia]

Hard to tell from those pics. Can you try for a closer/crisper image?

 

Tossing out a guess - limpets?

[TROLL]

I have them all over in one of my frag tank... Not even sure but they seems to colonize algaes that are growing on plugs. I guess some kind of coralline algae since they're flat disc.