- Petroderma maculiforme (Wollny) Kuckuck, 1897
- Ralfsia bornetii Kuckuck, 1894 accepted as Stragularia clavata (Harvey) Hamel, 1939
- Ralfsia disciformis P.L.Crouan & H.M.Crouan, 1867 accepted as Stragularia clavata (Harvey) Hamel, 1939
- Ralfsia expansa (J.Agardh) J.Agardh, 1848 accepted as Neoralfsia expansa (J.Agardh) P.-E.Lim & H.Kawai ex Cormaci & G.Furnari, 2012
- Ralfsia fungiformis (Gunnerus) Setchell & N.L.Gardner, 1924
- Ralfsia lucida S.Lund, 1967
- Ralfsia ovata Rosenvinge, 1893
- Ralfsia pusilla (Strömfelt) Foslie, 1892
- Ralfsia verrucosa (Areschoug) Areschoug, 1845