[Description of Lamellodiscus confusus n. sp, (Monogenea: Diplectanidae), parasite of Sarpa salpa (Teleostei: Sparidae)].

Lamellodiscus confusus n. sp., a diplectanid gill parasite of Sarpa salpa Linnaeus, 1758 (Sparidae) from the coast of Algeria, is described. This monogenean has been previously reported in Sarpa salpa, by various authors, under the name L. ignoratus. L. confusus n. sp. is included (among other Lamellodiscus of Mediterranean sparids) in the "ignoratus" sub-group (Amine & Euzet, 2005). L. confusus n. sp. can be distinguished from L. ignoratus by the shape and size of the haptoral ventral bar and the male copulatory organ. For comparison, illustrations of the ventral bar and the male copulatory organ of all Mediterranean species of the "ignoratus" sub-group are provided. The question of the host specificity of L. ignoratus is discussed.