White soft spot growing on rock, snail shell, etc.

[dmsc2fs]

Trying to figure out what this is that is starting to grow in my DT. They are softish as I can push them flat. They do not appear to be spirorbid from what I have seen in a few reference photo's. I'm not an expert though

so it could be. Any thoughts?

 

[JGT]

Snail eggs. Looks like nerite.

 

[dmsc2fs]

that is a probably answer. I have lots of nerite's in the tank. Thank you!