A new species of Geoplana Stimpson, 1857, registered for the National Forest of São Francisco de Paula, Rio Grande do Sul, Brasil, is described. Geoplana rubidolineata sp. nov. has a characteristic colour pattern, as well as a combination of characters of the internal morphology, which differentiate it from other species presenting a lining in the female atrium with multilayered aspect.
Geoplaninae; land planarian; morphology; taxonomy