Stylommatophora

Stylommatophora, one of the two groups of Mollusca forming the Pulmonata (q.v.). It is characterised by the fact that the eyes are situated on the extremities of a pair of tentacles, which may be retracted or expanded at will. The group includes many well-known Mollusca, such as the snails Helix, Papa, Clausilia; the slugs Arion, Limax, Testacella; etc.