Three Antarctic species of
Pionosyllis Malmgren, 1867 (Polychaeta: Syllidae: Eusyllinae) including
P. maxima Monro, 1930;
P. anops Hartman, 1953, and
P. epipharynx Hartman, 1953, are synonymous. They are redescribed and referred to
Eusyllis maxima (Monro, 1930), new combination, based on morphological characters, most notably the presence of an incomplete crown of denticles on the opening of the pharynx.