Sycon Risso, 1826

Streptoconus australis Jenkin, 1908

Sycon abyssale Borojevic & Graat-Kleeton, 1965

Sycon acanthoxea (Little, 1963)

Sycon album Tanita, 1942

Sycon ampulla (Haeckel, 1870)

Sycon antarcticum (Jenkin, 1908)

Sycon arcticum (Haeckel, 1870)

Sycon asperum (Gibson, 1886)

Sycon australe (Jenkin, 1908)

Sycon barbadense (Schuffner, 1877)

Sycon boreale (Schuffner, 1877)

Sycon brasiliense Borojevic, 1971

Sycon calcaravis Hozawa, 1929

Sycon caminatum Thacker, 1908

Sycon capricorn Wörheide & Hooper, 2003

Sycon carteri Dendy, 1893

Sycon ciliata (Fabricius, 1780)

Sycon ciliatum (Fabricius, 1780)

Sycon coactum (Urban, 1906)

Sycon compactum Lambe, 1893

Sycon cylindricum Tanita, 1942

Sycon defendens Borojevic, 1967

Sycon digitiforme Hozawa, 1929

Sycon dunstervillia (Haeckel, 1872)

Sycon eglintonense Lambe, 1900

Sycon elegans (Bowerbank, 1845)

Sycon ensiferum Dendy, 1893

Sycon escanabense Duplessis & Reiswig, 2000

Sycon escanabensis Duplessis & Reiswig, 2000

Sycon faulkneri Ilan, Gugel, Galil & Janussen, 2003

Sycon formosum (Haeckel, 1870)

Sycon frustulosum Borojevic & Peixinho, 1976

Sycon gelatinosum (Blainville, 1834)

Sycon giganteum Dendy, 1893

Sycon globulatum Hozawa, 1929

Sycon grantioides Dendy, 1916

Sycon helleri (Lendenfeld, 1891)

Sycon hozawai Breitfuss, 1932

Sycon huinayense Azevedo, Hajdu, Willenz & Klautau, 2009

Sycon humboldti Risso, 1826

Sycon inconspicuum (Lendenfeld, 1885)

Sycon incrustans Breitfuss, 1898

Sycon karajakense Breitfuss, 1897

Sycon kerguelense Urban, 1908

Sycon lambei Dendy & Row, 1913

Sycon lendenfeldi Row & Hozawa, 1931

Sycon lingua (Haeckel, 1870)

Sycon longstaffi (Jenkin, 1908)

Sycon lunulata (Haeckel, 1872)

Sycon lunulatum (Haeckel, 1872)

Sycon luteolum Tanita, 1942

Sycon matsushimense Tanita, 1940

Sycon mexico Hozawa, 1940

Sycon minutum Dendy, 1893

Sycon misakiense Hozawa, 1929

Sycon misakiensis Hozawa, 1929

Sycon mundulum Lambe, 1900

Sycon munitum Jenkin, 1908

Sycon natalense Borojevic, 1967

Sycon okadai Hozawa, 1929

Sycon ornatum Kirk, 1898

Sycon parvulum (Preiwisch, 1904)

Sycon pedicellatum Kirk, 1897

Sycon pentactinale Rossi, Farina, Borojevic & Klautau, 2006

Sycon plumosum Tanita, 1943

Sycon proboscideum (Haeckel, 1870)

Sycon procumbens Haeckel, 1872

Sycon protectum Lambe, 1896

Sycon pulchrum Tanita, 1943

Sycon quadrangulatum (Schmidt, 1868)

Sycon quadrata (Schuffner, 1877)

Sycon ramsayi (Lendenfeld, 1885)

Sycon raphanus Schmidt, 1862

Sycon rotundum Tanita, 1941

Sycon satsumense Hozawa, 1929

Sycon scaldiense (Van Koolwijk, 1982)

Sycon schmidti (Haeckel, 1872)

Sycon schuffneri Dendy & Row, 1913

Sycon setosum Schmidt, 1862

Sycon simushirense Hozawa, 1918

Sycon simushirensis Hozawa, 1918

Sycon stauriferum (Preiwisch, 1904)

Sycon subhispidum (Carter, 1886)

Sycon sycandra (Lendenfeld, 1895)

Sycon tabulatum (Schuffner, 1877)

Sycon tenellum Lendenfeld, 1891

Sycon tuba Lendenfeld, 1891

Sycon tubulosum (Haeckel, 1872)

Sycon urugamii Tanita, 1940

Sycon verum Row & Hozawa, 1931

Sycon vigilans Sarà & Gaino, 1971

Sycon villosum (Haeckel, 1870)

Sycon yatsui Hozawa, 1929