p. 95 - 122 BEITRAG ZUR KENNTNIS DER GATTUNG TETRASTEMMA (HOPLONEMERTINI) Geza Iuliu Muller Institut Roumain de Recherches Marines Constanta Abstract The paper presents a revision of the pontic species belonging to the genus Tetrastemma(Hoplonemertini), including a detailed redescription of the species Tetrastemma bacescui G. J. Muller 1962 and the original description of Tetrastemma glandulidorsum n. sp. Based upon analysis of generic and specific differential characters, the author proposes a new generic diagnosis, in order to eliminate the hitherto collective status of this genus. A key for identification of the mediterranean and pontic species, as well as some ecological notes are also given.