Confidence: I'm as sure as I can be.
Notes: Really attractive specimen. The marbling is the body surface showing through. Shape is not unlike Physa, but with sharper spire, much more flared mouth, and reverse spiral. If the spire (point) is upward, and the mouth (where the animal comes out) facing you, the opening is on the right in Lymnaea, so the shell is dextral. In Physa, spire up, mouth toward you, the mouth is on the left.