• Crucigera formosa Bush, 1905 accepted as Crucigera zygophora (Johnson, 1901)
• Crucigera hespera Chamberlin, 1919 accepted as Crucigera zygophora (Johnson, 1901)
• Crucigera inconstans Straughan, 1967
• Crucigera irregularis Bush, 1905
• Crucigera loveni (Kinberg, 1867) accepted as Serpula narconensis Baird, 1864
• Crucigera tricornis Gravier, 1906
• Crucigera websteri Benedict, 1887
• Crucigera zygophora (Johnson, 1901)
• Floriprotis sabiuraensis Uchida, 1978
• Hydroides (Eucarphus) benzoni Mörch, 1863 accepted as Hydroides dirampha Mörch, 1863
• Hydroides (Eucarphus) crucigera Mörch, 1863 [original] accepted as Hydroides crucigera Mörch, 1863
• Hydroides (Eucarphus) cumingii Mörch, 1863 accepted as Hydroides dirampha Mörch, 1863
• Hydroides (Eucarphus) cumingii navalis Mörch, 1863 accepted as Hydroides dirampha Mörch, 1863
• Hydroides (Eucarphus) dirampha Mörch, 1863 [original] accepted as Hydroides dirampha Mörch, 1863
• Hydroides (Eucarphus) infundibulum (Delle Chiaje, 1822) accepted as Vermiliopsis labiata (O. G. Costa, 1861)
• Hydroides (Eucarphus) microtis Mörch, 1863 accepted as Hydroides microtis Mörch, 1863
• Hydroides (Eucarphus) sanctaecrucis Krøyer in Mörch, 1863 accepted as Hydroides sanctaecrucis Krøyer in Mörch, 1863
• Hydroides (Eupomatus) blumenbachii Mörch, 1863 accepted as Eupomatus blumenbachii (Mörch, 1863)
• Hydroides (Eupomatus) dianthoides Augener, 1922 [original] accepted as Hydroides sanctaecrucis Krøyer in Mörch, 1863
• Hydroides (Eupomatus) dunkeri Mörch, 1863 [original] accepted as Hydroides gairacensis Augener, 1934
• Hydroides (Eupomatus) exaltatus (Marenzeller, 1884) accepted as Hydroides exaltata (Marenzeller, 1884)
• Hydroides (Eupomatus) fusicola Mörch, 1863 [original] accepted as Hydroides fusicola Mörch, 1863
• Hydroides (Eupomatus) gairacensis Augener, 1934 [original] accepted as Hydroides gairacensis Augener, 1934
• Hydroides (Eupomatus) novaepommeraniae Augener, 1925 accepted as Hydroides novaepommeraniae Augener, 1925
• Hydroides (Eupomatus) ralumianus Augener, 1927 [original name] accepted as Hydroides ralumiana Augener, 1927
• Hydroides abbreviata Krøyer [in] Mörch, 1863 [original name] accepted as Hydroides elegans (Haswell, 1883) [nomen protectum]
• Hydroides adamaformis Pillai, 2009
• Hydroides affinis (Marion, 1876) (uncertain > taxon inquirendum)
• Hydroides alatalateralis (Jones, 1962)
• Hydroides albiceps (Grube, 1870)
• Hydroides amri Sun, Wong, ten Hove, Hutchings, Williamson & Kupriyanova, 2015
• Hydroides ancorispina Pillai, 1971 [original]
• Hydroides arnoldi Augener, 1918
• Hydroides augeneri Zibrowius, 1973
• Hydroides azorica Zibrowius, 1972 [original]
• Hydroides azoricus Zibrowius, 1972 accepted as Hydroides azorica Zibrowius, 1972 [original]
• Hydroides bandaensis Zibrowius, 1972
• Hydroides bannerorum Bailey-Brock, 1991
• Hydroides basispinosa Straughan, 1967
• Hydroides basispinosus Straughan, 1967 [original] accepted as Hydroides basispinosa Straughan, 1967
• Hydroides benzoni Mörch, 1863 accepted as Hydroides dirampha Mörch, 1863
• Hydroides bifida Imajima, 1982 accepted as Hydroides furcifera (Grube, 1878)
• Hydroides bifidus Imajima, 1982 [original] accepted as Hydroides furcifera (Grube, 1878)
• Hydroides bifurcata Pixell, 1913
• Hydroides bifurcatus Pixell, 1913 accepted as Hydroides bifurcata Pixell, 1913
• Hydroides bisecta Imajima & ten Hove, 1989
• Hydroides bisectus Imajima & ten Hove, 1989 accepted as Hydroides bisecta Imajima & ten Hove, 1989
• Hydroides bispinosa Bush, 1910
• Hydroides bispinosus Bush, 1910 accepted as Hydroides bispinosa Bush, 1910
• Hydroides brachyacantha Rioja, 1941
• Hydroides brachyacanthus Rioja, 1941 accepted as Hydroides brachyacantha Rioja, 1941
• Hydroides bulbosa ten Hove, 1990
• Hydroides bulbosus ten Hove, 1990 [original] accepted as Hydroides bulbosa ten Hove, 1990
• Hydroides californicus Treadwell, 1929 [original] accepted as Hydroides crucigera Mörch, 1863
• Hydroides calopoma Zibrowius, 1973
• Hydroides capensis Zibrowius, 1972
• Hydroides caribensis ten Hove in Kupriyanova, Sun, Wong & ten Hove, 2023
• Hydroides centrospina Wu & Chen, 1981 accepted as Hydroides longispinosa Imajima, 1976 [original]
• Hydroides chilensis Hartmann-Schröder, 1962
• Hydroides cruciger Mörch, 1863 accepted as Hydroides crucigera Mörch, 1863
• Hydroides crucigera Mörch, 1863
• Hydroides cumingii (Mörch, 1863) accepted as Hydroides dirampha Mörch, 1863
• Hydroides dafnii (Amoureux, Rullier & Fishelson, 1978)
• Hydroides decorus (Treadwell, 1931) accepted as Hydroides floridana (Bush, 1910)
• Hydroides deleoni Bastida-Zavala & ten Hove, 2003
• Hydroides dianthoides Augener, 1922 accepted as Hydroides sanctaecrucis Krøyer in Mörch, 1863
• Hydroides dianthus (Verrill, 1873)
• Hydroides diplochone (Grube, 1878) (uncertain > taxon inquirendum)
• Hydroides dipoma (Schmarda, 1861)
• Hydroides dirampha Mörch, 1863
• Hydroides diramphus Mörch, 1863 accepted as Hydroides dirampha Mörch, 1863
• Hydroides dolabrus Tovar-Hernández, Villalobos-Guerrero, Kupriyanova & Sun, 2016
• Hydroides dunkeri Mörch, 1863 accepted as Hydroides gairacensis Augener, 1934
• Hydroides elegans (Haswell, 1883) [nomen protectum]
• Hydroides elegantula (Bush, 1910)
• Hydroides elegantulus (Bush, 1910) accepted as Hydroides elegantula (Bush, 1910)
• Hydroides esoensis [auct.] accepted as Hydroides ezoensis Okuda, 1934
• Hydroides euplaeana (Delle Chiaje, 1822 [1828?]) (uncertain > taxon inquirendum)
• Hydroides exaltata (Marenzeller, 1884)
• Hydroides exaltata vesiculosa Fauvel, 1919 (uncertain > taxon inquirendum)
• Hydroides exaltatus (Marenzeller, 1885) accepted as Hydroides exaltata (Marenzeller, 1884)
• Hydroides exaltatus vesiculosus Fauvel, 1919 accepted as Hydroides exaltata vesiculosa Fauvel, 1919
• Hydroides externispina Straughan, 1967
• Hydroides externispinosa [auct. lapsus] accepted as Hydroides externispina Straughan, 1967
• Hydroides ezoensis Okuda, 1934
• Hydroides floridana (Bush, 1910)
• Hydroides furcifera (Grube, 1878)
• Hydroides fusca Imajima, 1976 [original]
• Hydroides fusicola Mörch, 1863
• Hydroides gairacensis Augener, 1934
• Hydroides glandifera Rioja, 1941
• Hydroides glandiferum Rioja, 1941 [original] accepted as Hydroides glandifera Rioja, 1941
• Hydroides glasbyi Sun, Wong, ten Hove, Hutchings, Williamson & Kupriyanova, 2015
• Hydroides gottfriedi Read, ten Hove, Sun & Kupriyanova, 2017
• Hydroides gracilis (Bush, 1905)
• Hydroides gradata Straughan, 1967 [original] accepted as Hydroides basispinosa Straughan, 1967
• Hydroides gradatus Straughan, 1967 accepted as Hydroides basispinosa Straughan, 1967
• Hydroides groenlandica Mörch, 1863 (uncertain > nomen dubium)
• Hydroides grubei Pillai, 1965 accepted as Hydroides novaepommeraniae Augener, 1925
• Hydroides helmata (Iroso, 1921)