Acanthocardia (Rudicardium) Coen, 1915 accepted as Acanthocardia J. E. Gray, 1851 (basis of record)
Audouinella parvula (Kylin) P.S.Dixon, 1976 accepted as Acrochaetium parvulum (Kylin) Hoyt, 1920 (additional source)
Audouinella sanctae-mariae (Darbishire) P.S.Dixon, 1976 accepted as Acrochaetium sanctae-mariae (Darbishire) Hamel, 1927 (additional source)
Bulbamphiascus angustifolius Klie, 1950 accepted as Bulbamphiascus imus (Brady, 1872) (basis of record)
Cirolana gallica Hansen, 1905 accepted as Natatolana gallica (Hansen, 1905) (basis of record)
Cyamus ceti (Linnaeus, 1758) (basis of record)
Cylindrocarpus berkeleyi (Greville) P.Crouan & H.Crouan, 1851 accepted as Petrospongium berkeleyi (Greville) Nägeli ex Kützing, 1858 (additional source)
Didemnum gelatinosum (Milne Edwards, 1841) accepted as Diplosoma listerianum (Milne Edwards, 1841) (additional source)
Entocladia flustrae (Reinke) W.R.Taylor, 1937 accepted as Epicladia flustrae Reinke, 1889 (additional source)
Entocladia wittrockii Wille, 1880 accepted as Ulvella wittrockii (Wille) R.Nielsen, C.J.O'Kelly & B.Wysor, 2013 (additional source)
Erythrodermis allenii Batters, 1900 accepted as Erythrodermis traillii (Holmes ex Batters) Guiry & Garbary, 1990 (additional source)
Grandidierella japonica Stephensen, 1938 (basis of record)
Jania corniculata (Linnaeus) J.V.Lamouroux, 1816 accepted as Jania rubens var. corniculata (Linnaeus) Yendo, 1905 (additional source)
Pneophyllum concollum Y.M.Chamberlain, 1983 accepted as Pneophyllum myriocarpum (P.Crouan & H.Crouan) Y.M.Chamberlain, 1983 (additional source)
Pogotrichum filiforme Reinke, 1892 (basis of record)
Polysiphonia insidiosa (J.Agardh) P.Crouan & H.Crouan, 1867 accepted as Neosiphonia harveyi (Bailey) M.-S.Kim, H.-G.Choi, Guiry & G.W.Saunders, 2001 accepted as Melanothamnus harveyi (Bailey) Díaz-Tapia & Maggs, 2017 (additional source)
Polysiphonia spiralis L.Batten, 1923 accepted as Polysiphonia stricta (Mertens ex Dillwyn) Greville, 1824 (additional source)