Limpet snail?

[tchat]

Shown with blue and white lighting. Little smooth ovals in the rock work near where my frogspawn is that came with several odd hitchhikers.

 

[Euphylliaphyle]

Do they have hard shells? How big are they?

 

[tchat]

Hard shell, fairly small. I found a larger specimen on the glass and placed it next to a pencil for reference. Definitely has a hard shell and some sort of flesh underneath. Photo of the top and bottom side

 

[StartingATank]

They kinda look like abalones, or stomatellas, but it is fairly hard to tell because they are so small.

 

[rayadog]

Kinda looks like a slipper snail. But I could see stomatella too.

 

[Baldyreef]

2nd vote for slipper snail, I wouldn't say stomatella though, I have to in my tank and they cant fully retract into their shells and always have a large portion of their bodies out of their shell unlike those