• Sycetta asconoides Breitfuss, 1896
• Sycetta conifera (Haeckel, 1870)
• Sycon abyssale Borojevic & Graat-Kleeton, 1965
• Sycon arcticum (Haeckel, 1870)
• Sycon asperum (Gibson, 1886) (uncertain > taxon inquirendum)
• Sycon asperum Schmidt, 1862 accepted as Leucandra aspera (Schmidt, 1862)
• Sycon boreale (Schuffner, 1877)
• Sycon ciliatum (Fabricius, 1780)
• Sycon coronatum (Ellis & Solander, 1786) accepted as Sycon ciliatum (Fabricius, 1780)
• Sycon elegans (Bowerbank, 1845)
• Sycon faulkneri Ilan, Gugel, Galil & Janussen, 2003
• Sycon helleri (Lendenfeld, 1891)
• Sycon humboldti Risso, 1827
• Sycon humboldtii accepted as Sycon humboldti Risso, 1827
• Sycon lambei Dendy & Row, 1913
• Sycon lingua (Haeckel, 1870)
• Sycon protectum Lambe, 1896
• Sycon quadrangulata (Schmidt, 1868) accepted as Sycon quadrangulatum (Schmidt, 1868)
• Sycon quadrangulatum (Schmidt, 1868)
• Sycon raphanus Schmidt, 1862
• Sycon scaldiense (Van Koolwijk, 1982)
• Sycon schmidti (Haeckel, 1872)
• Sycon schuffneri Dendy & Row, 1913
• Sycon setosum Schmidt, 1862
• Sycon sycandra (Lendenfeld, 1895)
• Sycon tenellum Lendenfeld, 1891 accepted as Sycantha tenella Lendenfeld, 1891
• Sycon tuba Lendenfeld, 1891
• Sycon villosum (Haeckel, 1870)