Freshwater snails » Shell shape » Shell taller than wide » Dextral shell with operculum Shell shape taller than it is wide, with the mouth on the right hand side, and closed by an operculum in the live animal. Please click on the appropriate image to continue These images are NOT all to the same scale. Scale bars are provided on each image. Greater than 25mm. high and shaped like this ? Shell rather squat, (or even flatter) with an almost circular mouth? Shell conical and adult more than 6mm high? Shell conical and adult less than 6mm high?