Limax marginatus O. F. Müller, 1774 Lehmannia marginata is a species of air-breathing land slug, a terrestrial pulmonate gastropod mollusk in the family Limacidae.

Sometimes classified in the genus Limax, the species is distinct in its ecology, and its nearly transparent body.

It is a medium-sized species, rarely exceeding 12 cm in body length.

The body is fairly long and narrow, with a marked keel.

The keel looks lighter than the remaining body against the darker innards.