Abstract: A new genus and species, Alistratia beroni n. gen. n. sp., is described from the cave Alistrati, North Greece. The new genus differs from all remaining genera of subfamily Haplophtalminae by the presence of a pair of paramedian tubercles on the first pleonal segment and an endopodit of the first pleopode formed by 3 articles. On the ground of these differences a new (fourth) group within the classification of Vandel (1967) with one representative, genus Alistratia, was initiated. The characteristics of the new genus confirm his views concerning the presence of numerous independent phyletic lines, which are subordinate to more or less parallel evolution trends.