Gastrosaccus lobatus Nouvel, 1951 accepted as Haplostylus lobatus (Nouvel, 1951)
Gastrosaccus magnilobatus Bacescu & Schiecke, 1974 accepted as Haplostylus magnilobatus (Bacescu & Schiecke, 1974)
Gastrosaccus mediterraneus Bacescu, 1970
Gastrosaccus normani G.O. Sars, 1877 accepted as Haplostylus normani (G.O. Sars, 1877)
Gastrosaccus roscoffensis Bacescu, 1970
Gastrosaccus sanctus (Van Beneden, 1861)
Gastrosaccus spinifer (Goës, 1864)
Gastrosaccus spiniferus (Goës, 1864) accepted as Gastrosaccus spinifer (Goës, 1864)
Gastrosaccus widhalmi (Czerniavsky, 1882)
Haplostylus bacescui Hatzakis, 1977
Haplostylus lobatus (Nouvel, 1951)
Haplostylus magnilobatus (Bacescu & Schiecke, 1974)
Haplostylus normani (G.O. Sars, 1877)