Caesicirrus nglectus – synonym of Euclymene oerstedi
Caesicirrus nglectus Arwidsson, 1911 – synonym of Euclymene oerstedi
Calamyzas amphictenicola Arwidsson, 1932 – synonym of Calamyzas amphictenicola
Capitella capitata McIntosh, 1915 – synonym of Capitella capitata
Capitella filiformis – synonym of Heteromastus filiformis
Capitella filiformis Claparède, 1864 – synonym of Heteromastus filiformis
Capitella giardi Warren, 1976 – synonym of Capitella giardi
Capitella minima Langerhans, 1880 – synonym of Capitella minima
Capitellides giardi – synonym of Capitella giardi
Capitellides giardi Mesnil, 1897 – synonym of Capitella giardi
Capitomastus giardi – synonym of Capitella giardi
Capitomastus giardi Hartman-Schröder, 1971 – synonym of Capitella giardi
Capitomastus minimus – synonym of Capitella minima
Capitomastus minimus Eisig, 1887 – synonym of Capitella minima
Castalia fusca – synonym of Kefersteinia cirrata
Castalia fusca McIntosh, 1908 – synonym of Kefersteinia cirrata
Castalia punctata – synonym of Nereimyra punctata
Castalia punctata McIntosh, 1908 – synonym of Nereimyra punctata
Caulleriella alata Hartmann-Schröder, 1971 – synonym of Caulleriella alata
Caulleriella bioculata Hartmann-Schröder, 1971 – synonym of Caulleriella bioculata
Caulleriella bioculata parva – synonym of Caulleriella parva
Caulleriella bioculata parva Gillandt, 1979 – synonym of Caulleriella parva
Caulleriella caput-esocis Hartmann-Schröder, 1971 – synonym of Caulleriella caput-esocis
Caulleriella killariensis – synonym of Tharyx killariensis
Caulleriella killariensis Eliason, 1962 – synonym of Tharyx killariensis
Caulleriella parva Hartmann-Schröder, 1996 – synonym of Caulleriella parva
Caulleriella serrata Eliason, 1962 – synonym of Caulleriella serrata
Ceratocephale borealis – synonym of Ceratocephale loveni
Ceratocephale borealis Wesenberg-Lund, 1950 – synonym of Ceratocephale loveni
Ceratocephale loveni Malmgren, 1867 – synonym of Ceratocephale loveni
Chaetoparia nilssoni Malmgren, 1867 – synonym of Chaetoparia nilssoni
Chaetopterus norvegicus – synonym of Chaetopterus variopedatus
Chaetopterus norvegicus Michaelsen, 1896 – synonym of Chaetopterus variopedatus
Chaetopterus sarsi – synonym of Chaetopterus variopedatus
Chaetopterus sarsi Michaelsen, 1896 – synonym of Chaetopterus variopedatus
Chaetopterus variopedatus McIntosh, 1914 – synonym of Chaetopterus variopedatus
Chaetozone alata – synonym of Caulleriella alata
Chaetozone alata Southern, 1914 – synonym of Caulleriella alata
Chaetozone killariensis – synonym of Tharyx killariensis
Chaetozone killariensis Southern, 1914 – synonym of Tharyx killariensis
Chaetozone setosa Malmgren, 1867 – synonym of Chaetozone setosa
Chitinopoma serrula Zibrowius, 1969 – synonym of Chitinopoma serrula
Chloraema edwardsi – synonym of Flabelligera affinis
Chloraema edwardsi Oersted, 1844 – synonym of Flabelligera affinis
Choe flabelligera – synonym of Euchone papillosa
Choe flabelligera Kröyer, 1856 – synonym of Euchone papillosa
Chone duneri Malmgren, 1867 – synonym of Chone duneri
Chone fauveli McIntosh, 1923 – synonym of Chone fauveli
Chone filicaudata Southern, 1914 – synonym of Chone filicaudata
Chone longocirrata Sars, 1872 – synonym of Chone longocirrata
Chone rubrocincta – synonym of Euchone rubrocincta
Chone rubrocincta M. Sars, 1861 – synonym of Euchone rubrocincta
Chrysopetalum caecum – synonym of Dysponetus caecus
Chrysopetalum caecum Langerhans, 1880 – synonym of Dysponetus caecus
Chrysopetalum debile – synonym of Paleaonotus debilis
Chrysopetalum debile Southern, 1914 – synonym of Paleaonotus debilis
Chrysopetalum fragile – synonym of Paleaonotus debilis
Chrysopetalum fragile Ehlers, 1864 – synonym of Paleaonotus debilis
Circeis armoricana Saint-Joseph, 1894 – synonym of Circeis armoricana
Circeis paguri – synonym of Circeis armoricana
Circeis paguri Knight-Jones, 1977 – synonym of Circeis armoricana
Circeis spirillum Knight-Jones & Knight-Jones, 1977 – synonym of Circeis spirillum
Cirratulus bioculatus – synonym of Caulleriella bioculata
Cirratulus bioculatus Keferstein, 1862 – synonym of Caulleriella bioculata
Cirratulus borealis – synonym of Cirratulus cirratus
Cirratulus borealis – synonym of Cirriformia tentaculata
Cirratulus borealis Oersted, 1843 – synonym of Cirratulus cirratus
Cirratulus borealis Rathke, 1843 – synonym of Cirriformia tentaculata
Cirratulus cirratus Fauvel, 1927 – synonym of Cirratulus cirratus
Cirratulus filiformis Keferstein, 1862 – synonym of Cirratulus filiformis
Cirratulus norvegicus – synonym of Cirriformia tentaculata
Cirratulus norvegicus Southern, 1914 – synonym of Cirriformia tentaculata
Cirratulus tentaculatus – synonym of Cirriformia tentaculata
Cirratulus tentaculatus McIntosh, 1913 – synonym of Cirriformia tentaculata
Cirriformia tentaculata Hartmann-Schröder, 1971 – synonym of Cirriformia tentaculata
Cirrophorus armatus Strelzov, 1973 – synonym of Cirrophorus armatus
Cirrophorus eliasoni Hartmann-Schröder 1996 – synonym of Cirrophorus eliasoni
Cirrophorus lyra Hartmann-Schröder, 1996 – synonym of Cirrophorus lyra
Cirrophorus lyra Strelzov, 1973 – synonym of Cirrophorus eliasoni
Cistenides hyperborea – synonym of Pectinaria hyperborea
Cistenides hyperborea Malmgren, 1866 – synonym of Pectinaria hyperborea
Clymene (E.) oerstedi – synonym of Euclymene oerstedi
Clymene (E.) oerstedi Fauvel, 1927 – synonym of Euclymene oerstedi
Clymene affinis – synonym of Praxillella affinis
Clymene affinis Sars, 1872 – synonym of Praxillella affinis
Clymene biceps – synonym of Chirimia biceps
Clymene biceps Sars, 1861 – synonym of Chirimia biceps
Clymene droebachiensis – synonym of Euclymene droebachiensis
Clymene droebachiensis M. Sars, 1872 – synonym of Euclymene droebachiensis
Clymene gracilis – synonym of Praxillella quadrilobata
Clymene gracilis Sars, 1861 part – synonym of Praxillella quadrilobata
Clymene intermedia – synonym of Praxillella praetermissa
Clymene intermedia Oersted, 1843 – synonym of Praxillella praetermissa
Clymene koreni – synonym of Maldane sarsi
Clymene koreni Hansen, 1882 – synonym of Maldane sarsi
Clymene lumbricalis – synonym of Nicomache lumbricalis
Clymene lumbricalis Moebius, 1874 – synonym of Nicomache lumbricalis
Clymene muelleri – synonym of Proclymene muelleri
Clymene muelleri Sars, 1856 – synonym of Proclymene muelleri
Clymene oerstedi – synonym of Euclymene oerstedi
Clymene oerstedi Claparède, 1863 – synonym of Euclymene oerstedi
Clymene planiceps – synonym of Isocirrus planiceps
Clymene planiceps Sars, 1872 – synonym of Isocirrus planiceps
Clymene praetermissa – synonym of Praxillella praetermissa
Clymene praetermissa Fauvel, 1927 – synonym of Praxillella praetermissa
Clymene quadrilobata – synonym of Praxillella quadrilobata
Clymene quadrilobata Sars, 1856 – synonym of Praxillella quadrilobata
Clymene robusta – synonym of Euclymene robusta
Clymene robusta Fauvel, 1927 – synonym of Euclymene robusta
Clymene torquatus – synonym of Clymenella torquata
Clymene torquatus Leidy, 1855 – synonym of Clymenella torquata
Clymenella torquata Verrill, 1873 – synonym of Clymenella torquata
Clymenura borealis – synonym of Clymenura lankesteri
Clymenura borealis Hartmann-Schröder, 1971 – synonym of Clymenura lankesteri
Clymenura lankesteri Imajima & Shiraki, 1982 – synonym of Clymenura lankesteri
Colobranchus ciliatus – synonym of Malacoceros tetracerus
Colobranchus ciliatus Söderström, 1920 – synonym of Malacoceros tetracerus
Colobranchus tetracerus – synonym of Malacoceros tetracerus
Colobranchus tetracerus Schmarda, 1861 – synonym of Malacoceros tetracerus
Commensodorum commensalis Kirkegaard, 1992 – synonym of Commensodorum commensalis
Cossura longocirrata Webster & Benedict, 1887 – synonym of Cossura longocirrata
Crossostoma midas – synonym of Amphicteis midas
Crossostoma midas Gosse, 1855 – synonym of Amphicteis midas
Ctenodrilus serratus Fauvel, 1927 – synonym of Ctenodrilus serratus
Ctenospio plumosa – synonym of Prionospio plumosa
Ctenospio plumosa Sars, 1872 – synonym of Prionospio plumosa