Amphora acutissima Giffen, 1980 (original description)
Amphora caroliniana Giffen, 1980 (original description)
Amphora pestilenta Giffen, 1980 (original description)
Amphora scopulorum Giffen, 1980 (original description)
Amphora vaughanii Giffen, 1980 (original description)
Cocconeis quarnerensis f. rhombica Giffen, 1980 (original description)
Coscinodiscus granulosus f. seychellensis Giffen, 1980 (original description)
Cyclotella pravissima Giffen, 1980 (original description)
Cymatoneis sulcata f. maheensis Giffen, 1980 (original description)
Haslea howeana (Hagelstein) Giffen, 1980 (new combination reference)
Haslea nautica (Cholnoky) Giffen, 1980 accepted as
Navicula nautica Cholnoky, 1963 (new combination reference)
Mastogloia binotata f. cuneata Giffen, 1980 (original description)
Navicula besarensis Giffen, 1980 (original description)
Navicula capillata Giffen, 1980 (original description)
Navicula lucenoides Giffen, 1980 (original description)
Nitzschia percuriosa Giffen, 1980 (original description)
Nitzschia pulchriora Giffen, 1980 (original description)
Oestrupia witti (Grunow) Giffen, 1980 accepted as
Navicula wittii Grunow in Cleve, 1881 (new combination reference)
Okedenia inflexa f. capitata Giffen, 1980 (original description)
Opephora anomala Giffen, 1980 (original description)
Opephora lineata Giffen, 1980 (original description)
Rhaphoneis mascarenae Giffen, 1980 (original description)
Synedra distinguenda var. curta Giffen, 1980 (original description)
Synedra tabulata var. lata Giffen, 1980 (original description)
Trachyneis velata f. alternata Giffen, 1980 (original description)
Tropidoneis seychellensis Giffen, 1980 (original description)