• Aciculaspio anaximanderi Blake & Ramey-Balci, 2020
• Amphipolydora abranchiata (Hartman, 1953)
• Amphipolydora vestalis Paterson & Gibson, 2003
• Anaspio boreus Chamberlin, 1920 (uncertain > nomen dubium)
• Aonidella cirrobranchiata (Day, 1961)
• Aonidella dayi López-Jamar, 1989
• Aonidella insolita (Greaves, Meißner & Wilson, 2011)
• Aonides auricularis Claparède, 1864 accepted as Aonides oxycephala (Sars, 1862)
• Aonides californiensis Rioja, 1947
• Aonides diverapoda Hoagland, 1920 accepted as Trochochaeta diverapoda (Hoagland, 1920)
• Aonides fulgens Levinsen, 1884 accepted as Paraonis fulgens (Levinsen, 1884)
• Aonides glandulosa Blake, 1996
• Aonides gracilis Tauber, 1879 accepted as Levinsenia gracilis (Tauber, 1879)
• Aonides mayaguezensis Foster, 1969
• Aonides nodosetosa Storch, 1966
• Aonides orensanzi Radashevsky, 2015
• Aonides oxycephala (Sars, 1862)
• Aonides oxycephala oligobranchia Wu, 1967 in Buzhinskaya, 1971
• Aonides paucibranchiata Southern, 1914
• Aonides selvagensis Brito, Nunez & Riera, 2006
• Aonides trifida Estcourt, 1967
• Aonis foliacea [Auctt.] accepted as Aonis foliosa Audouin & Milne Edwards, 1833 accepted as Scolelepis foliosa (Audouin & Milne Edwards, 1833) represented as Scolelepis (Scolelepis) foliosa (Audouin & Milne Edwards, 1833)
• Aonis foliosa Audouin & Milne Edwards, 1833 accepted as Scolelepis foliosa (Audouin & Milne Edwards, 1833) represented as Scolelepis (Scolelepis) foliosa (Audouin & Milne Edwards, 1833)
• Aonis vittata Grube, 1855 accepted as Scolelepis (Scolelepis) foliosa (Audouin & Milne Edwards, 1833)
• Aonis wagneri Frey & Leuckart, 1847
• Aonopsis agilis Wagner, 1885 (unaccepted > nomen nudum)
• Apistobranchus fragmentata (Wesenberg-Lund, 1951)
• Apistobranchus glacierae Hartman, 1978
• Apistobranchus gudrunae Hartmann-Schröder & Rosenfeldt, 1988 accepted as Apistobranchus glacierae Hartman, 1978
• Apistobranchus gundrunae [auct. misspelling] accepted as Apistobranchus gudrunae Hartmann-Schröder & Rosenfeldt, 1988 accepted as Apistobranchus glacierae Hartman, 1978
• Apistobranchus jasoni Neal & Paterson, 2020
• Apistobranchus ornatus Hartman, 1965
• Apistobranchus tenuis Orrhage, 1962
• Apistobranchus tullbergi (Théel, 1879)
• Apistobranchus typicus (Webster & Benedict, 1887)
• Apoprionospio caspersi (Laubier, 1962) accepted as Prionospio caspersi Laubier, 1962
• Apoprionospio dayi Foster, 1969
• Apoprionospio dayi japonica Imajima, 1989 accepted as Apoprionospio japonica Imajima, 1989
• Apoprionospio japonica Imajima, 1989
• Apoprionospio nova (Annenkova, 1938) accepted as Prionospio nova Annenkova, 1938
• Apoprionospio pygmaea (Hartman, 1961)
• Apoprionospio saldanha (Day, 1961) accepted as Prionospio saldanha Day, 1961
• Apoprionospio sanguarensis Delgado-Blas & Fonseca-González, 2023
• Apoprionospio vermillionensis (Fauchald, 1972) accepted as Prionospio vermillionensis Fauchald, 1972
• Aquilaspio peruana (Hartmann-Schröder, 1962) accepted as Prionospio peruana Hartmann-Schröder, 1962
• Aquilaspio pyramidalis Hutchings & Turvey, 1984 accepted as Prionospio pyramidalis (Hutchings & Turvey, 1984)
• Aquilaspio sexoculata (Augener, 1918) accepted as Prionospio sexoculata Augener, 1918
• Aricideopsis megalops Johnson, 1901 accepted as Laonice cirrata (M. Sars, 1851)
• Asetocalamyzas laonicola Tzetlin, 1985 accepted as Scolelepis laonicola (Tzetlin, 1985)
• Atherospio aestuarii Abe & Kan, 2022
• Atherospio disticha Mackie & Duff, 1986
• Atherospio guillei (Laubier & Ramos, 1974)
• Aurospio abranchiata Neal, Paterson & Soto in Paterson et al., 2016
• Aurospio banyulensis (Laubier, 1966)
• Aurospio dibranchiata Maciolek, 1981
• Aurospio foodbancsia Mincks, Dyal, Paterson, Smith & Glover, 2009
• Aurospio pilkena (Wilson, 1990)
• Aurospio tribranchiata Paterson & Soto in Paterson et al., 2016
• Australospio mokapu Ward, 1981
• Australospio trifida Blake & Kudenov, 1978
• Boccardia (Boccardia) androgyna Read, 1975 accepted as Boccardia androgyna Read, 1975
• Boccardia (Boccardia) magniovata Read, 1975 accepted as Boccardiella magniovata (Read, 1975)
• Boccardia (Boccardia) wellingtonensis Read, 1975 accepted as Boccardia wellingtonensis Read, 1975
• Boccardia (Paraboccardia) acus (Rainer, 1973) represented as Boccardia acus (Rainer, 1973)
• Boccardia (Paraboccardia) knoxi (Rainer, 1973) represented as Boccardia knoxi (Rainer, 1973)
• Boccardia (Paraboccardia) lamellata (Rainer, 1973) represented as Boccardia lamellata (Rainer, 1973)
• Boccardia (Paraboccardia) syrtis (Rainer, 1973) represented as Boccardia syrtis (Rainer, 1973)
• Boccardia acus (Rainer, 1973)
• Boccardia androgyna Read, 1975
• Boccardia basilaria Hartman, 1961
• Boccardia berkeleyorum Blake & Woodwick, 1971
• Boccardia chilensis Blake & Woodwick, 1971
• Boccardia columbiana Berkeley, 1927
• Boccardia fleckera Hutchings & Turvey, 1984
• Boccardia galapagense Blake, 1986
• Boccardia hamata (Webster, 1879) accepted as Boccardiella hamata (Webster, 1879)
• Boccardia jubata Rainer, 1973
• Boccardia knoxi (Rainer, 1973)
• Boccardia lamellata (Rainer, 1973)
• Boccardia ligerica Ferronnière, 1898 accepted as Boccardiella ligerica (Ferronnière, 1898)
• Boccardia limnicola Blake & Woodwick, 1976 accepted as Boccardiella limnicola (Blake & Woodwick, 1976)
• Boccardia magniovata Read, 1975 accepted as Boccardiella magniovata (Read, 1975)
• Boccardia natrix (Söderström, 1920)
• Boccardia otakouica Rainer, 1973
• Boccardia perata (Chlebovitsch, 1959)
• Boccardia polybranchia (Haswell, 1885)
• Boccardia proboscidea Hartman, 1940
• Boccardia pseudonatrix Day, 1961
• Boccardia pugettensis Blake, 1979
• Boccardia redeki (Horst, 1920) accepted as Boccardiella ligerica (Ferronnière, 1898)
• Boccardia salazari Delgado-Blas, 2008
• Boccardia semibranchiata Guérin, 1990
• Boccardia syrtis (Rainer, 1973)
• Boccardia tricuspa (Hartman, 1939)
• Boccardia truncata Hartman, 1936 accepted as Boccardiella truncata (Hartman, 1936)
• Boccardia uncata Berkeley, 1927 accepted as Boccardiella hamata (Webster, 1879)
• Boccardia wellingtonensis Read, 1975
• Boccardiella bihamata Blake & Kudenov, 1978
• Boccardiella hamata (Webster, 1879)
• Boccardiella ligerica (Ferronnière, 1898)