Can anyone identify these?

[dabroli]

They’re white, spreading, all over certain rocks and some of my snail shells. Before anyone suggests nerite egg sacs, I do not have any nerite snails. I don’t believe they are worm or snails themselves because they are flat, round, and with any orifices. I was able to break or “pop” one with my tweezers. They don’t move at all and some even have algae growing on them. I’m at a loss lol.

 

[Rocks reef]

Can you dislodge one and take a picture of the underside?

 

[lilzman8]

Could be foraminiferans, harmless unless you don't like the look of them