Deutsch: Posthornschnecke (Planorbarius corneus) in einem Graben bei Riddagshausen (Braunschweig/Deutschland)
English: Great Ramshorn (Planorbarius corneus) in a ditch near Riddagshausen (Braunschweig/Germany)
Date 22 March 2012
Author Donkey shot https://commons.wikimedia.org/wiki/User:Donkey_shot
Source: https://commons.wikimedia.org/wiki/File:Wasserschnecke002.JPG

The great ramshorn snail (Planorbarius corneus) is a relatively large species of air-breathing freshwater snail, an aquatic pulmonate gastropod mollusk in the family Planorbidae. The shell of this species appears to be dextral in coiling, even though it is in fact sinistral or left-handed.