Achnanthes obtusa Ehrenberg in Ralfs in Pritchard, 1861 (original description)
Achnanthidium trinode Ralfs, 1861 (original description)
Actinocyclus acharneus Ralfs in Pritchard, 1861 (original description)
Actinocyclus astrolites Ralfs in Pritchard, 1861 (original description)
Actinocyclus bet-el-gose Ralfs in Pritchard, 1861 (original description)
Actinocyclus crassus (W.Smith) Ralfs ex Pritchard, 1861 accepted as
Eupodiscus crassus W.Smith, 1853 (new combination reference)
Actinocyclus ehrenbergii f. ehrenbergii Ralfs in Pritchard, 1861 (original description)
Actinocyclus fulvus (W.Smith) Ralfs ex Pritchard, 1861 accepted as
Eupodiscus fulvus W. Smith, 1853 (new combination reference)
Actinocyclus interpunctatus (Brightwell) Ralfs in Pritchard, 1861 accepted as
Actinoptychus interpunctatus Brightwell, 1860 (new combination reference)
Actinocyclus moniliformis var. moniliformis Ralfs in Pritchard, 1861 (original description)
Actinocyclus omphus Ralfs in Pritchard, 1861 (original description)
Actinocyclus ralfsii var. ralfsii (W. Smith) Ralfs in Pritchard, 1861 accepted as
Eupodiscus ralfsii var. ralfsii W. Smith, 1856 (new combination reference)
Actinocyclus ralfsii var. sparsus (Gregory) Ralfs, 1861 accepted as
Eupodiscus sparsus Gregory, 1857 (new combination reference)
Actinocyclus subtilis var. subtilis (Gregory) Ralfs in Pritchard, 1861 accepted as
Eupodiscus subtilis Gregory, 1857 (new combination reference)
Actinocyclus tessellatus (Roper) Ralfs ex Pritchard, 1861 accepted as
Eupodiscus tesselatus Roper, 1858 represented as
Roperia tesselata (Roper) Grunow ex Pelletan, 1889 (new combination reference)
Actinoptychus elegans Ralfs in Pritchard, 1861 (original description)
Actinoptychus spinosus (Brightwell) Ralfs in Pritchard, 1861 accepted as
Actinocyclus spinosus Brightwell, 1860 (new combination reference)
Actinoptychus splendens f. splendens (Shadbolt) Ralfs in Pritchard, 1861 accepted as
Actinophaenia splendens Shadbolt, 1854 (new combination reference)
Actinoptychus trilingulatus var. trilingulatus (Brightwell) Ralfs in Pritchard, 1861 accepted as
Actinocyclus trilingulatus Brightwell, 1860 (new combination reference)
Actinoptychus undulatus f. undulatus (Kützing) Ralfs in Pritchard, 1861 accepted as
Actinocyclus undulatus Kützing, 1844 (new combination reference)
Amphicampa (C.G. Ehrenberg) J. Ralfs in A. Pritchard, 1861 (original description)
Amphicampa mirabilis Ehrenberg ex Ralfs, 1861 † (original description)
Amphipentas flexuosa J.W. Bailey in Ralfs in Pritchard, 1861 † (original description)
Amphitetras crucifera Kitton in Ralfs in Pritchard, 1861 (original description)
Amphora gregorii Ralfs., 1861 (original description)
Amphora marina Ralfs in Pritchard, 1861 (original description)
Arthrogyra C.G. Ehrenberg ex Ralfs in Pritchard, 1861 (original description)
Arthrogyra guatimalensis Ehrenberg ex Ralfs in Pritchard, 1861 (original description)
Arthrogyra semilunaris Ehrenberg ex Ralfs in Pritchard, 1861 (original description)
Asterodiscus johnsoni Ralfs, 1852 (original description)
Asteromphalus arachne var. arachne (Brébisson) Ralfs in Pritchard, 1861 accepted as
Spatangidium arachne Brébisson, 1857 (new combination reference)
Asteromphalus dallasianus (Greville) Ralfs in Pritchard, 1861 accepted as
Asterolampra dallasiana Greville, 1860 (new combination reference)
Asteromphalus heptactis (Brébisson) Ralfs, 1861 (new combination reference)
Asteromphalus hiltonianus (Greville) Ralfs in Pritchard, 1861 (new combination reference)
Asteromphalus roperianus var. roperianus (Greville) Ralfs in Pritchard, 1861 accepted as
Asterolampra roperiana Greville, 1860 (new combination reference)
Asteromphalus shadboltianus (Greville) Ralfs in Pritchard, 1861 accepted as
Asterolampra shadboltiana Greville, 1860 (new combination reference)
Asteromphalus stellatus (Greville) Ralfs in Pritchard, 1861 (new combination reference)
Asteromphalus wallichianus (Greville) Ralfs in Pritchard, 1861 accepted as
Asterolampra wallichiana Greville, 1860 (new combination reference)
Aulacodiscus barbadensis Ralfs in Pritchard, 1861 (original description)
Aulacodiscus beeveriae var. beeveriae Johnson ex Pritchard, 1861 (original description)
Aulacodiscus boliviensis Brébisson manuscript in Pritchard, 1861 (original description)
Aulacodiscus brightwellii Ralfs ms. in Pritchard, 1861 (original description)
Aulacodiscus brownei Norman ex Pritchard, 1861 (original description)
Aulacodiscus comberi var. comberi Arnott ex Pritchard, 1861 (original description)
Aulacodiscus formosus var. formosus Arnott ex Pritchard, 1861 (original description)
Aulacodiscus johnsonii Arnott ex Pritchard, 1861 (original description)
Aulacodiscus kittonii var. kittoni Arnott ex Ralfs in Pritchard, 1861 (original description)
Aulacodiscus margaritaceus var. margaritaceus Ralfs in Pritchard, 1861 (original description)
Aulacodiscus pulcher var. pulcher Norman in Pritchard, 1861 (original description)
Aulacodiscus scaber var. scaber Ralfs in Pritchard, 1861 (original description)
Aulacodiscus sollittianus G.Norman, 1861 (original description)
Auliscus ovalis Arnott ex Pritchard, 1861 (original description)
Auliscus polystigmus (Ehrenberg) Ralfs in Pritchard, 1861 accepted as
Coscinodiscus polystigma Ehrenberg, 1843 (new combination reference)
Auliscus sculptus var. sculptus (W. Smith) Ralfs in Pritchard, 1861 accepted as
Eupodiscus sculptus W.Smith, 1853 (new combination reference)
Bacillaria naegeli Ralfs in Pritchard, 1861 (original description)
Bacillaria socialis var. socialis (Gregory) Ralfs in Pritchard, 1861 accepted as
Nitzschia socialis var. socialis Gregory, 1857 (new combination reference)
Bacteriastrum wallichii var. wallichii Ralfs in Pritchard, 1861 (original description)
Biddulphia amphicephala (Ehrenberg) Ralfs in Pritchard, 1861 accepted as
Odontella amphicephala Ehrenberg, 1845 (new combination reference)
Biddulphia fragilaria (Ehrenberg) Ralfs in Pritchard, 1861 accepted as
Denticella fragilaria Ehrenberg, 1844 (new combination reference)
Biddulphia macdonaldii Norman in Pritchard, 1861 (original description)
Biddulphia obtusa f. obtusa (Kützing) Ralfs in Pritchard, 1861 accepted as
Odontella obtusa Kützing, 1844 (new combination reference)
Biddulphia polymera (Ehrenberg) Ralfs in Pritchard, 1861 accepted as
Denticella polymera Ehrenberg, 1844 (1845) (new combination reference)
Biddulphia subaequa var. subaequa (Kützing) Ralfs in Pritchard, 1861 accepted as
Odontella subaequa var. subaequa Kützing, 1844 (new combination reference)
Biddulphia turgida (Ehrenberg) W.Smith, 1856 accepted as
Denticella turgida Ehrenberg, 1840 (new combination reference)
Brightwellia J. Ralfs in A. Pritchard, 1861 † (original description)
Brightwellia coronata var. coronata (Brightwell) Ralfs in Pritchard, 1861 accepted as
Craspedodiscus coronatus Brightwell, 1860 † (new combination reference)
Campylodiscus concinnus Greville ex Ralfs in Pritchard, 1861 (original description)
Campylodiscus ehrenbergii Ralfs in Pritchard, 1861 (original description)
Campylodiscus elegans (Ehrenberg) Ralfs in Pritchard, 1861 accepted as
Surirella elegans f. elegans Ehrenberg, 1843 (new combination reference)
Campylodiscus flexuosa (Ehrenberg) Ralfs in Pritchard, 1861 accepted as
Surirella flexuosa Ehrenberg, 1843 accepted as
Spirodiscina flexuosa (Ehr.) S.Blanco & C.E.Wetzel, 2016 (new combination reference)
Campylodiscus myodon (Ehrenberg) Ralfs in Pritchard, 1861 accepted as
Surirella myodon Ehrenberg, 1843 (new combination reference)
Campylodiscus normanicus 'Greville' Ralfs in Pritchard, 1861 (original description)
Campylodiscus ovatus Ralfs, 1861 (original description)
Cerataulus laevis var. laevis (Ehrenberg) Ralfs in Pritchard, 1861 accepted as
Biddulphia laevis f. laevis Ehrenberg, 1843 (new combination reference)
Cerataulus smithii var. smithii Ralfs in Pritchard, 1861 accepted as
Ralfsiella smithii (Ralfs in Pritchard) P.A. Sims, D. M. Williams & Ashworth, 2018 (original description)
Cerataulus thermalis var. thermalis (Meneghini) Ralfs in Pritchard, 1861 accepted as
Melosira thermalis Meneghini, 1845 (new combination reference)
Ceratoneis acicularis (Kützing) Ralfs in Pritchard, 1861 accepted as
Synedra acicularis Kützing, 1844 (new combination reference)
Ceratoneis linea (Ehrenberg) Ralfs in Pritchard, 1861 accepted as
Synedra linea Ehrenberg, 1844 (new combination reference)
Ceratoneis reversa (W. Smith) Ralfs in Pritchard, 1861 accepted as
Nitzschia reversa f. reversa W. Smith, 1853 (new combination reference)
Ceratoneis rhomboides Ehrenberg in Ralfs in Pritchard, 1861 (original description)
Chaetoceros confervoides Ralfs in Pritchard, 1861 (original description)
Cocconeis brasiliensis Ehrenberg in Ralfs in Pritchard, 1861 (original description)
Coscinodiscus cervinus (Brightwell) Ralfs in Pritchard, 1861 accepted as
Hyalodiscus cervinus Brightw., 1860 † (new combination reference)
Coscinodiscus excavatus var. excavatus Greville manuscript, Ralfs in Pritchard, 1861 (original description)
Craspedodiscus barbadensis Ralfs in Pritchard, 1861 (original description)
Cyclotella atlantica (Ehrenberg) Ralfs in Pritchard, 1861 accepted as
Discoplea atlantica Ehrenberg, 1854 (new combination reference)
Cyclotella atmosphaerica Ralfs accepted as
Discoplea atmosphaerica Ehrenberg, 1847 (new combination reference)
Cyclotella dendochaera (Ehrenberg) Ralfs in Pritchard, 1861 accepted as
Discoplea dendrochaera Ehrenberg, 1848 (new combination reference)
Cyclotella graeca var. graeca (Ehrenberg) Ralfs in Pritchard, 1861 accepted as
Lindavia graeca (Ehrenberg) Nakov et al., 2015 (new combination reference)
Cyclotella oligactis Ralfs accepted as
Discoplea oligactis Ehrenberg, 1854 (new combination reference)
Cyclotella oregonica (Ehrenberg) Ralfs, 1861 accepted as
Discoplea oregonica Ehrenberg, 1854 (new combination reference)
Cyclotella rectangula Brébisson ex Rabenhorst, 1853 (original description)
Cyclotella sinensis (Ehrenberg) Ralfs in Pritchard, 1861 accepted as
Discoplea sinensis Ehrenberg, 1847 (new combination reference)
Cyclotella umbilicata (Ehrenberg) Ralfs in Pritchard, 1861 accepted as
Discoplea umbilicata Ehrenberg, 1854 (new combination reference)
Cyclotella undulata (Ehrenberg) Ralfs in Pritchard, 1861 accepted as
Discoplea undulata Ehrenberg, 1854 (new combination reference)
Cyclotella venusta (Ehrenberg) Ralfs in Pritchard, 1861 accepted as
Discoplea venusta Ehrenberg, 1852 (new combination reference)
Cymatopleura elliptica var. torta Tempère & Peragallo, 1913 (original description)
Cymatopleura heterocyma (Naegeli in Kützing) Ralfs in Pritchard, 1861 accepted as
Surirella heterocyma Naegeli in Kützing, 1849 (new combination reference)
Cymatopleura multifasciata (Kützing) Ralfs in Pritchard, 1861 accepted as
Frustulia multifasciata Kützing, 1833 (1834) (new combination reference)
Cymatopleura ovum (Nägeli) Ralfs in Pritchard, 1861 accepted as
Surirella ovum Naegeli ex Kützing, 1849 (new combination reference)