• Arachnactis albida Sars, 1846
• Arachnactis bournei Fowler, 1897 accepted as Cerianthus lloydii Gosse, 1859 accepted as Synarachnactis lloydii (Gosse, 1859)
• Arachnactis brachiolata A. Agassiz, 1863 accepted as Synarachnactis brachiolata (A. Agassiz, 1863)
• 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
• Isarachnactis longipes Carlgren, 1924
• Isarachnanthus cruzi Brito, 1986 accepted as Isarachnanthus maderensis (Johnson, 1861)
• Isarachnanthus maderensis (Johnson, 1861)
• Isarachnanthus nocturnus (Hartog, 1977)