This bell mouth ram's horn snail is native to Maine - yay! - and we have them living in Lake Arrowhead. The shell is a flat spiral, as opposed to the ice cream swirl type of shell of the invasive Chinese mystery snail. It's an aquatic snail that breathes air and feeds on algae.
We also have a conically spiraled snail that breathes with gills, also living in our lake but it has been introduced. It gives birth to fully developed young snails that mysteriously and suddenly appear.