Acigonium spinosa (Greville) P.A.Sims & D.M.Williams in Sims et al., 2018 † (new combination reference)
Amphitetras bicornis (Cleve) De Toni, 1894 † accepted as
Pseudictyota bicorne (Cleve) P.A. Sims & D. M. Williams in Sims et al., 2018 † (new combination reference)
Biddulphia dubia (T.Brightwell) Cleve, 1883 accepted as
Pseudictyota dubium (Brightwell) P.A. Sims & D. M. Williams in Sims et al., 2018 (new combination reference)
Biddulphia peruviana Grunow in Van Heurck, 1882 † accepted as
Ralfsiella peruviana (Grunow in Van Heurck) P.A. Sims, D. M. Williams & M. Ashworth, 2018 † (new combination reference)
Biddulphia plana Schmidt in Schmidt et al., 1888 accepted as
Pseudictyota plana (A. Schmidt) P.A. Sims & D. M. Williams in Sims et al., 2018 (new combination reference)
Biddulphia reticulata var. dubia (Brightwell) Cleve, 1883 accepted as
Pseudictyota dubium (Brightwell) P.A. Sims & D. M. Williams in Sims et al., 2018 (new combination reference)
Biddulphia ruthenica Witt, 1885 † accepted as
Parodontella ruthenica (Witt) D M.Williams & P.A.Sims in Sims et al., 2018 † (additional source)
Biddulphia smithii (Ralfs in Pritchard) Van Heurck, 1885 accepted as
Ralfsiella smithii (Ralfs in Pritchard) P.A. Sims, D. M. Williams & Ashworth, 2018 (new combination reference)
Biddulphia tenuicornis Greville, 1865 † accepted as
Parodontella tenuicornis (Greville) D. M. Williams & P.A. Sims in Sims et al., 2018 † (source of synonymy)
Biddulphia tumida var. peruviana Grunow in Van Heurck, 1882 † accepted as
Ralfsiella peruviana (Grunow in Van Heurck) P.A. Sims, D. M. Williams & M. Ashworth, 2018 † (new combination reference)
Cerataulus granulatus (Roper) P.A. Sims & D.M. Williams, 2018 † (new combination reference)
Cerataulus strelnikovae P.A. Sims & D. M. Williams in Sims et al, 2018 † (original description)
Denticella granulata (Roper) Van Heurck, 1896 † accepted as
Cerataulus granulatus (Roper) P.A. Sims & D.M. Williams, 2018 † (new combination reference)
Denticella ruthenica (Witt) De Toni, 1894 † accepted as
Parodontella ruthenica (Witt) D M.Williams & P.A.Sims in Sims et al., 2018 † (additional source)
Denticella tumida var. peruviana (Grunow in Van Heurck) De Toni, 1894 † accepted as
Ralfsiella peruviana (Grunow in Van Heurck) P.A. Sims, D. M. Williams & M. Ashworth, 2018 † (new combination reference)
Hobaniella P.A. Sims & D. M. Williams in Sims et al, 2018 (original description)
Hobaniella longicruris (Greville) P.A. Sims & D.M. Williams in Sims et al., 2018 (new combination reference)
Odontella granulata (Roper) R.Ross in Hartley, 1986 † accepted as
Cerataulus granulatus (Roper) P.A. Sims & D.M. Williams, 2018 † (new combination reference)
Odontella plana (Schmidt in Schmidt et al.) De Toni, 1894 accepted as
Pseudictyota plana (A. Schmidt) P.A. Sims & D. M. Williams in Sims et al., 2018 (new combination reference)
Odontellaceae P.A. Sims, D.M. Williams & Ashworth, 2018 (original description)
Odontotropis tenuicornis (Greville) De Toni, 1894 † accepted as
Parodontella tenuicornis (Greville) D. M. Williams & P.A. Sims in Sims et al., 2018 † (source of synonymy)
Parodontella calamus (J. Tempère & J. Brun) S. Komura, 1999 † (additional source)
Parodontella fimbriata (Greville) D. M. Williams & P.A. Sims in Sims et al., 2018 † (new combination reference)
Parodontella obliqua S. Komura, 1999 † accepted as
Parodontella tenuicornis (Greville) D. M. Williams & P.A. Sims in Sims et al., 2018 † (source of synonymy)
Parodontella ruthenica (Witt) D M.Williams & P.A.Sims in Sims et al., 2018 † (new combination reference)
Parodontella tenuicornis (Greville) D. M. Williams & P.A. Sims in Sims et al., 2018 † (new combination reference)
Pseudictyota P.A.Sims & D.M.Williams in Sims et al., 2018 (original description)
Pseudictyota bicorne (Cleve) P.A. Sims & D. M. Williams in Sims et al., 2018 † (new combination reference)
Pseudictyota dubium (Brightwell) P.A. Sims & D. M. Williams in Sims et al., 2018 (new combination reference)
Pseudictyota plana (A. Schmidt) P.A. Sims & D. M. Williams in Sims et al., 2018 (new combination reference)
Ralfsiella P.A. Sims, D. M. Williams & Ashworth, 2018 (original description)
Ralfsiella minima (Grunow in Van Heurck) P.A. Sims & D. M. Williams in Sims et al., 2018 (new combination reference)
Ralfsiella peruviana (Grunow in Van Heurck) P.A. Sims, D. M. Williams & M. Ashworth, 2018 † (new combination reference)
Ralfsiella smithii (Ralfs in Pritchard) P.A. Sims, D. M. Williams & Ashworth, 2018 (new combination reference)
Triceratium bicorne Cleve, 1878 † accepted as
Pseudictyota bicorne (Cleve) P.A. Sims & D. M. Williams in Sims et al., 2018 † (new combination reference)
Triceratium dubium Brightwell, 1859 accepted as
Pseudictyota dubium (Brightwell) P.A. Sims & D. M. Williams in Sims et al., 2018 (new combination reference)
Holotype BM 101831, identified as
Cerataulus strelnikovae P.A. Sims & D. M. Williams in Sims et al, 2018