On the occurrence in Southern Italy of some benthic marine algae rare to the Mediterranean Sea. - The Authors report the occurrence along the coast of Southern Italy of the following species that resulted rare to the Mediterranean Sea:Antithamnion piliferumCormaci et Furnari;Bonnemaisonia asparagoides(Woodward) C. Agardh (tetrasporophyte);Corynophlaea flaccidaKuetzing;Fosliella farinosa(Lamouroux) Howe: of this very common species, the occurrence of thalli with propagules is reported;Hypnea cervicornisJ. Agardh;Jania adherensLamouroux, new to Italy;Mesogloia lanosaP.L. et H.M. Crouan, new to Italy;Pneophyllum confervicolum(Kuetzing) Chamberlain f.minutulum(Foslie) Chamberlain, new to the Mediterranean Sea;Polystrata fosliei(Weber van Bosse) Denizot, new to Italy;Rhodymenia delicatulaDangeard;Spermothamnion johannisG. Feldmann-Mazoyer: of this common species, the occurrence of bisporocysts in monoic gametophytes is reported;Vickersia baccata(J. Agardh) Karsakoff.