- Gomphonemopsis exigua (Kützing) Medlin in Medlin & Round, 1986 (uncertain > unassessed)
- Gomphonemopsis pseudexigua (Simonsen) Medlin in Medlin & Round, 1986 accepted as Gomphonema pseudoexiguum Simonsen, 1959
- Gomphosphenia grovei (M.Schmidt) Lange-Bertalot, 1995
- Rhoicosphenia abbreviata (C.Agardh) Lange-Bertalot, 1980
- Rhoicosphenia curvata (Kützing) Grunow, 1860 accepted as Rhoicosphenia abbreviata (C.Agardh) Lange-Bertalot, 1980
- Rhoicosphenia curvata var. marina (Kützing) Rabenhorst, 1864 accepted as Gomphonema curvatum var. marinum Kützing, 1844
- Rhoicosphenia curvata var. marina Grunow sensu Wuorentaus, 1912 accepted as Rhoicosphenia abbreviata (C.Agardh) Lange-Bertalot, 1980
- Rhoicosphenia marina (Kützing) M.Schmidt, 1889