what is this???

[mikea213]

So i was looking for a coral that fell off and i found a old disc in the sand. I took it to find these on it.

 

[Sniperhank]

Doesn't look like the stomallia snail...I'd say flat worm.

 

[mikea213]

What damage do they do and how do i get rid of them?

 

[Sniperhank]

I've never battled them myself, so knowledge is limited. This might help.
Pests Invading the Reef Aquarium Hobby: Part 2 - Flatworms, Snails & Limpets

 

[mikea213]

Here is a little better pic. They were way in the sand. They dont look like the pics of flat worms i just looked at. There oval brownish red with a black center