What is in my snail?

[Squeven]

I’ve had this snail for a couple of months, and didn’t think anything of the white spot that was on it. Tonight I was looking at everything, and saw this white spot open like a small clam.
It’s an almost pearl white, and very hard. Anyone have an idea of what it is? Is it going to effect my coral? Any help would be great. (Still working in my photo skills.)

 

[fishguy242]

hi,poss clam?? @KJ

 

[flampton]

I'm guessing some type of barnacle but what type no clue. Did it have feeders sticking out when open? I guess could be a weird clam as well if you don't see feeders

 

[samnaz]

Probably a limpet.

 

[fishguy242]

Probably a limpet.

i was thinking that,but rippled edge??

 

[KJ]

Bivalve.

 

[Squeven]

I'm guessing some type of barnacle but what type no clue. Did it have feeders sticking out when open? I guess could be a weird clam as well if you don't see feeders

I didn’t see any feeders, but I will look again when the snail comes out of hiding.