• Sycetta antarctica Brøndsted, 1931
• Sycetta asconoides Breitfuss, 1896
• Sycetta conifera (Haeckel, 1870)
• Sycetta cupula Haeckel, 1872 accepted as Grantia cupula (Haeckel, 1872)
• Sycetta papillata Mattedi & Cavalcanti, 2024
• Sycetta perforata (Haeckel, 1872)
• Sycetta primitiva Haeckel, 1872
• Sycetta quadriradiata Hôzawa, 1929
• Sycetta sagitta de Laubenfels, 1942
• Sycetta sagittifera Haeckel, 1872
• Sycetta stauridia Haeckel, 1872 accepted as Sycettusa stauridia (Haeckel, 1872)
• Sycetta strobilus Haeckel, 1872 accepted as Grantia strobilus (Haeckel, 1872)
• Sycetta vinitincta Van Soest & De Voogd, 2015
• Sycon abyssale Borojevic & Graat-Kleeton, 1965
• Sycon acanthoxea (Little, 1963)
• Sycon album Tanita, 1942
• Sycon ampulla (Haeckel, 1870)
• Sycon ampullum accepted as Sycon ampulla (Haeckel, 1870)
• Sycon ancora Klautau, Imesek, Azevedo, Plese, Nikolic & Cetkovic, 2016
• Sycon antarcticum (Jenkin, 1908)
• Sycon arcticum (Haeckel, 1870) accepted as Grantia arctica (Haeckel, 1872)
• Sycon arcticum var. maximum (Haeckel, 1872) accepted as Sycon arcticum (Haeckel, 1870) accepted as Grantia arctica (Haeckel, 1872)
• Sycon asperum (Gibson, 1886) (uncertain > taxon inquirendum)
• Sycon asperum Lambe, 1896 accepted as Sycon lambei Dendy & Row, 1913
• Sycon asperum Schmidt, 1862 accepted as Leucandra aspera (Schmidt, 1862)
• Sycon australe (Jenkin, 1908)
• Sycon avus Chagas & Cavalcanti, 2017
• Sycon barbadense (Schuffner, 1877)
• Sycon bellum Chagas & Cavalcanti, 2017
• Sycon boomerang Dendy, 1893 accepted as Grantessa boomerang (Dendy, 1893)
• Sycon boreale (Schuffner, 1877)
• Sycon brasiliense Borojevic, 1971
• Sycon calcaravis Hôzawa, 1929
• Sycon caminatum Thacker, 1908
• Sycon capillosus (Schmidt, 1862) accepted as Grantia capillosa (Schmidt, 1862)
• Sycon capricorn Wörheide & Hooper, 2003
• Sycon carteri Dendy, 1893
• Sycon ciliatum (Fabricius, 1780)
• Sycon ciliatum var. polaris Breitfuss, 1898 accepted as Sycon hozawai Breitfuss, 1932
• Sycon ciliatum var. spinispiculum (Carter, 1876)
• Sycon coactum (Urban, 1906)
• Sycon compactum Lambe, 1893
• Sycon compressum (Fabricius, 1780) accepted as Grantia compressa (Fabricius, 1780)
• Sycon conulosum Cóndor-Luján, Louzada, Hajdu & Klautau, 2018
• Sycon coronatum (Ellis & Solander, 1786) accepted as Sycon ciliatum (Fabricius, 1780)
• Sycon cylindricum Tanita, 1942
• Sycon defendens Borojevic, 1967
• Sycon dendyi Kirk, 1895 accepted as Sycute dendyi (Kirk, 1895)
• Sycon digitiforme Hôzawa, 1929
• Sycon dunstervillia (Haeckel, 1872)
• Sycon eglintonense Lambe, 1900
• Sycon eglintonensis Lambe, 1900 accepted as Sycon eglintonense Lambe, 1900
• Sycon elegans (Bowerbank, 1845)
• Sycon ensiferum Dendy, 1893
• Sycon escanabense Duplessis & Reiswig, 2000
• Sycon escanabensis Duplessis & Reiswig, 2000 accepted as Sycon escanabense Duplessis & Reiswig, 2000
• Sycon faulkneri Ilan, Gugel, Galil & Janussen, 2003
• Sycon formosum (Haeckel, 1870)
• Sycon frustulosum Borojevic & Peixinho, 1976
• Sycon gelatinosum (Blainville, 1834)
• Sycon gelatinosum var. whiteleggei Dendy, 1893 accepted as Sycon gelatinosum (Blainville, 1834)
• Sycon giganteum Dendy, 1893
• Sycon globulatum Hôzawa, 1929
• Sycon grantioides Dendy, 1916
• Sycon helleri (Lendenfeld, 1891)
• Sycon hozawai Breitfuss, 1932
• Sycon huinayense Azevedo, Hajdu, Willenz & Klautau, 2009
• Sycon humboldti Risso, 1827
• Sycon humboldtii accepted as Sycon humboldti Risso, 1827
• Sycon inconspicuum (Lendenfeld, 1885)
• Sycon incrustans Breitfuss, 1898
• Sycon karajakense Breitfuss, 1897
• Sycon kerguelense Urban, 1908
• Sycon lambei Dendy & Row, 1913
• Sycon lendenfeldi Row & Hôzawa, 1931
• Sycon lingua (Haeckel, 1870)
• Sycon longstaffi (Jenkin, 1908) accepted as Sycantha longstaffi (Jenkin, 1908)
• Sycon lunulatum (Haeckel, 1872)
• Sycon luteolum Tanita, 1942
• Sycon magnapicale Cóndor-Luján, Louzada, Hajdu & Klautau, 2018
• Sycon matsushimense Tanita, 1940
• Sycon mexico Hôzawa, 1940
• Sycon minutum Dendy, 1892
• Sycon misakiensis Hôzawa, 1929
• Sycon mundulum Lambe, 1900
• Sycon munitum Jenkin, 1908
• Sycon natalense Borojevic, 1967
• Sycon okadai Hôzawa, 1929
• Sycon ornatum Kirk, 1897
• Sycon oscari Van Soest & De Voogd, 2018
• Sycon parvulum (Preiwisch, 1904)
• Sycon pedicellatum Kirk, 1897
• Sycon pentactinale Rossi, Farina, Borojevic & Klautau, 2006
• Sycon petiolatum Schmidt in Haeckel, 1870 accepted as Sycon ampulla (Haeckel, 1870)
• Sycon plumosum Tanita, 1943
• Sycon poireti Risso, 1827 (uncertain > taxon inquirendum)
• Sycon proboscideum (Haeckel, 1870)
• Sycon protectum Lambe, 1896 accepted as Grantia arctica (Haeckel, 1872)
• Sycon pulchrum Tanita, 1943
• Sycon quadrangulata (Schmidt, 1868) accepted as Sycon quadrangulatum (Schmidt, 1868)