• Tetrastemma Ehrenberg, 1831
• Tetrastemma aberrans Coe, 1901
• Tetrastemma aequicolor Chernyshev, 2024
• Tetrastemma agricola Willemoes-Suhm, 1874 accepted as Prosadenoporus agricola (Willemoes-Suhm, 1874)
• Tetrastemma albicollis Ushakov, 1928 accepted as Amphiporus superbus (Girard in Stimpson, 1854)
• Tetrastemma albidum Coe, 1905 accepted as Prosorhochmus albidus (Coe, 1905)
• Tetrastemma albolineatum (Timofeeva, 1912) (uncertain > nomen dubium)
• Tetrastemma albomaculatum Chernyshev, 2016
• Tetrastemma album Hookabe, Kohtsuka, Fujiwara, Tsuchida & Ueshima, 2023
• Tetrastemma algae (Dalyell, 1853) accepted as Tetrastemma candidum (Müller, 1774)
• Tetrastemma ambiguum Riches, 1893
• Tetrastemma amphiporoides Bürger, 1893
• Tetrastemma angulatus Senz, 1993
• Tetrastemma antarcticum Bürger, 1893
• Tetrastemma appendiculatum Chernyshev, 1998
• Tetrastemma arctica Ushakov, 1926 accepted as Arctostemma arcticum (Ushakov, 1926)
• Tetrastemma arcticum Ushakov, 1926 accepted as Arctostemma arcticum (Ushakov, 1926)
• Tetrastemma arenicola Verrill, 1873 accepted as Lineus arenicola (Verrill, 1873)
• Tetrastemma armatum J. V. Carus, 1885 accepted as Tetrastemma quatrefagesi (Bürger, 1904)
• Tetrastemma aseptata (Friedrich, 1935)
• Tetrastemma assimile Örsted, 1844
• Tetrastemma bacescui Müller, 1962
• Tetrastemma baculus (Quatrefages, 1846)
• Tetrastemma basinum Corrêa, 1957
• Tetrastemma beaumonti (Southern, 1913)
• Tetrastemma belgica accepted as Antarctonemertes belgica (Bürger, 1904)
• Tetrastemma belgicae Bürger, 1904 accepted as Antarctonemertes belgica (Bürger, 1904)
• Tetrastemma benedeni Czerniavsky, 1880
• Tetrastemma bicolor Coe, 1901
• Tetrastemma bilineatum Coe, 1904
• Tetrastemma bioculatum Örsted, 1843
• Tetrastemma bipeltatum (Timofeeva, 1912) (uncertain > nomen dubium)
• Tetrastemma bistriatum (Timofeeva, 1912)
• Tetrastemma bobi Corrêa, 1961 accepted as Tetrastemma worki Corrêa, 1961
• Tetrastemma brunnea (Friedrich, 1935) (uncertain > nomen dubium)
• Tetrastemma buxeum Bürger, 1895
• Tetrastemma caecum Coe, 1901 accepted as Amphinemertes caeca (Coe, 1901)
• Tetrastemma candida (Müller, 1774) accepted as Tetrastemma candidum (Müller, 1774)
• Tetrastemma candidum (Müller, 1774)
• Tetrastemma capitata Lebedinsky, 1889 accepted as Tetrastemma capitatum Lebedinsky, 1889
• Tetrastemma capitatum Lebedinsky, 1889 (uncertain > nomen dubium)
• Tetrastemma carneum Hookabe, Oya, Tsuchida, Fujiwara & Ueshima, 2023
• Tetrastemma cassidens (Marenzeller, 1886) (uncertain > nomen dubium)
• Tetrastemma cephalophorum Bürger, 1895 (uncertain > nomen dubium)
• Tetrastemma cerasinum Bürger, 1895
• Tetrastemma cincum Corrêa, 1957
• Tetrastemma commensalis (Kyao, 1954) accepted as Asteronemertes commensalis (Kyao, 1954)
• Tetrastemma coronatum (Quatrefages, 1846)
• Tetrastemma cruciatum Bürger, 1895
• Tetrastemma cruciatus sensu Senz, 1993 accepted as Tetrastemma kirsteueri Senz, 1995
• Tetrastemma cupido Hookabe, Kohtsuka & Kajihara, 2021
• Tetrastemma diadema Hubrecht, 1879
• Tetrastemma dilutebasisae Kulikova, 1987 accepted as Antarctonemertes dilutebasisae (Kulikova, 1987) accepted as Kurilonemertes dilutebasisae (Kulikovae, 1987)
• Tetrastemma dubium Örsted, 1845
• Tetrastemma duboisi Bürger, 1893
• Tetrastemma dutoiti (Wheeler, 1940)
• Tetrastemma elegans (Girard, 1852)
• Tetrastemma elongatum (Stephenson, 1911)
• Tetrastemma enteroplecta (Corrêa, 1954)
• Tetrastemma esbenseni Wheeler, 1934 accepted as Oerstedia esbenseni (Wheeler, 1934)
• Tetrastemma falsum Bürger, 1895
• Tetrastemma flagellatum Montgomery, 1897 accepted as Tetrastemma vermiculus (Quatrefages, 1846)
• Tetrastemma flavida McIntosh, 1873-1874 accepted as Nemertopsis flavida (McIntosh, 1873-1874)
• Tetrastemma flavidum Ehrenberg, 1828
• Tetrastemma flavidum var. longissima accepted as Tetrastemma flavidum Ehrenberg, 1828
• Tetrastemma flavidum var. longissimum accepted as Tetrastemma flavidum Ehrenberg, 1828
• Tetrastemma fozense Gibson & Junoy, 1991
• Tetrastemma fozensis Gibson & Junoy, 1991 accepted as Tetrastemma fozense Gibson & Junoy, 1991
• Tetrastemma freyae Chernyshev, Polyakova, Vignesh, Jain, Sanjeevi, Norenburg & Rajesh, 2020
• Tetrastemma fulvum Kirsteuer, 1963
• Tetrastemma georgianum Bürger, 1893
• Tetrastemma glandulidorsum Müller, 1976 (unaccepted > nomen nudum)
• Tetrastemma glanduliferum Bürger, 1895
• Tetrastemma graecensis Böhmig, 1892 accepted as Prostoma graecense (Böhmig, 1892)
• Tetrastemma graeffei (Diesing, 1863) (uncertain > nomen dubium)
• Tetrastemma groenlandicum Diesing, 1850 accepted as Tetrastemma candidum (Müller, 1774)
• Tetrastemma gulliveri Bürger, 1893 accepted as Oerstedia gulliveri (Bürger, 1893)
• Tetrastemma hansi Bürger, 1893
• Tetrastemma helvolum Bürger, 1895 (uncertain > nomen dubium)
• Tetrastemma hermaphroditica (Keferstein, 1868) accepted as Tetrastemma hermaphroditicum (Keferstein, 1868)
• Tetrastemma hermaphroditicum (Keferstein, 1868)
• Tetrastemma herouardi (Oxner, 1908)
• Tetrastemma herthae Corrêa, 1963
• Tetrastemma humile (Quatrefages, 1846)
• Tetrastemma humilis (Quatrefages, 1846) accepted as Tetrastemma humile (Quatrefages, 1846)
• Tetrastemma immutabile Riches, 1893 accepted as Oerstedia immutabilis (Riches, 1893)
• Tetrastemma incisum Stimpson, 1855
• Tetrastemma insicum accepted as Tetrastemma incisum Stimpson, 1855
• Tetrastemma insolens Iwata, 1952
• Tetrastemma interruptum Bürger, 1895
• Tetrastemma jeani McCaul, 1963
• Tetrastemma kangauzi Chernyshev, 2003
• Tetrastemma kefersteinii (Marion, 1869)
• Tetrastemma kefersteinii sensu Joubin, 1890 accepted as Tetrastemma hermaphroditica (Keferstein, 1868) accepted as Tetrastemma hermaphroditicum (Keferstein, 1868)
• Tetrastemma kirsteueri Senz, 1995
• Tetrastemma knochi accepted as Tetrastemma knochii (Kölliker, 1845)
• Tetrastemma knochii (Kölliker, 1845)
• Tetrastemma kulikovae Gibson, 1995 accepted as Protetrastemma viride (Kulikova, 1989)
• Tetrastemma lacustre du Plessis, 1892 accepted as Prostoma graecense (Böhmig, 1892)
• Tetrastemma laminariae Ushakov, 1928