• Arachnactis albida Sars, 1846
• Arachnactis bournei Fowler, 1897 accepted as Cerianthus lloydii Gosse, 1859 accepted as Synarachnactis lloydii (Gosse, 1859)
• Arachnactis lloydii (Gosse, 1859) accepted as Cerianthus lloydii Gosse, 1859 accepted as Synarachnactis lloydii (Gosse, 1859)
• Arachnanthus nocturnus den Hartog, 1977 accepted as Isarachnanthus nocturnus (Hartog, 1977)
• Arachnanthus oligopodus (Cerfontaine, 1891)
• Arachnanthus sarsi Carlgren, 1912
• Botracnidifer norvegicus Carlgren, 1912 accepted as Botrucnidifer norvegicus Carlgren, 1912
• Botrucnidifer norvegicus Carlgren, 1912
• Cerianthula mediterranea Beneden, 1897
• Cerianthus dohrni van Beneden, 1924 accepted as Pachycerianthus dohrni (van Beneden, 1924)
• Cerianthus lloydi Gosse, 1859 accepted as Cerianthus lloydii Gosse, 1859 accepted as Synarachnactis lloydii (Gosse, 1859)
• Cerianthus lloydii Gosse, 1859 accepted as Synarachnactis lloydii (Gosse, 1859)
• Cerianthus membranaceous accepted as Cerianthus membranaceus (Gmelin, 1791)
• Cerianthus membranaceus (Gmelin, 1791)
• Cerianthus vogti Danielssen, 1890
• Isarachnactis longipes Carlgren, 1924
• Isarachnanthus cruzi Brito, 1986 accepted as Isarachnanthus maderensis (Johnson, 1861)
• Isarachnanthus maderensis (Johnson, 1861)
• Isarachnanthus nocturnus (Hartog, 1977)
• Pachycerianthus dohrni (van Beneden, 1924)
• Pachycerianthus multiplicatus Carlgren, 1912
• Pachycerianthus solitarius (Rapp, 1829)
• Synarachnactis bournei (Fowler, 1897) accepted as Cerianthus lloydii Gosse, 1859 accepted as Synarachnactis lloydii (Gosse, 1859)
• Synarachnactis lloydii (Gosse, 1859)
• Synarachnactis membranacea (Gmelin, 1791) accepted as Cerianthus membranaceus (Gmelin, 1791)