Slug type thing

[LegendaryCG]

I see this in my sump any idea what it is? Its crawling around on the glass.

 

[Spare time]

I think its a stomatella. If so, they are fantastic free snails.

 

[BranchingHammer]

Hard to tell with the lighting in the picture, but probably a stomatella snail. Can you use a flashlight or something else to get a white light photo?