Aartsenia Warén, 1991 (basis of record)
Aartsenia Warén, 1991 (extant flag source)
Acanthochitona Gray, 1821 (basis of record)
Acanthodoris Gray, 1850 (basis of record)
Acanthodoris Gray, 1850 (extant flag source)
Acesta H. Adams & A. Adams, 1858 (basis of record)
Acirsa Mörch in Rink, 1857 (basis of record)
Aclis Lovén, 1846 (basis of record)
Acrilloscala Sacco, 1890 (basis of record)
Acrochalix Bouchet & Warén, 1986 (basis of record)
Acrochalix Bouchet & Warén, 1986 (extant flag source)
Adalaria Bergh, 1878 accepted as Onchidoris Blainville, 1816 (basis of record)
Adalaria Bergh, 1878 accepted as Onchidoris Blainville, 1816 (extant flag source)
Addisonia Dall, 1882 (extant flag source)
Addisonia Dall, 1882 (basis of record)
Adeuomphalus Seguenza, 1876 (basis of record)
Aeolidia Cuvier, 1798 (extant flag source)
Aeolidia Cuvier, 1798 (basis of record)
Afrocardium Tomlin, 1931 (basis of record)
Aglaja Renier, 1807 (basis of record)
Aglaja Renier, 1807 (extant flag source)
Akritogyra Warén, 1992 (basis of record)
Akritogyra Warén, 1992 (extant flag source)
Alaba H. Adams & A. Adams, 1853 (basis of record)
Alderella Odhner in Franc, 1968 (extant flag source)
Alderella Odhner in Franc, 1968 (basis of record)
Alexandromenia Heath, 1911 (extant flag source)
Alexandromenia Heath, 1911 (basis of record)
Algarvia García-Gómez & Cervera, 1989 (basis of record)
Algarvia García-Gómez & Cervera, 1989 (extant flag source)
Aliceia Dautzenberg & H. Fischer, 1897 (extant flag source)
Aliceia Dautzenberg & H. Fischer, 1897 (basis of record)
Allogramma Dall, 1903 (basis of record)
Allogramma Dall, 1903 (extant flag source)
Alloteuthis Wülker, 1920 (extant flag source)
Alloteuthis Wülker, 1920 (basis of record)
Alora H. Adams, 1861 (extant flag source)
Alora H. Adams, 1861 (basis of record)
Alvania Risso, 1826 (basis of record)
Ammonicera Vayssière, 1893 (extant flag source)
Ammonicera Vayssière, 1893 (basis of record)
Amphimenia Thiele, 1894 (extant flag source)
Amphimenia Thiele, 1894 (basis of record)
Amphiplica Haszprunar, 1988 (extant flag source)
Amphiplica Haszprunar, 1988 (basis of record)
Amphirissoa Dautzenberg & Fischer, 1897 (basis of record)
Amphirissoa Dautzenberg & Fischer, 1897 (extant flag source)
Amphissa H. Adams & A. Adams, 1853 (basis of record)
Ampulla Röding, 1798 (basis of record)
Anamenia Nierstrasz, 1908 (basis of record)
Anamenia Nierstrasz, 1908 (extant flag source)
Ancistrobasis Dall, 1889 (extant flag source)
Ancistrobasis Dall, 1889 (basis of record)
Ancistrosyrinx Dall, 1881 (basis of record)
Ancistroteuthis Gray, 1849 (extant flag source)
Ancistroteuthis Gray, 1849 (basis of record)
Anekes Bouchet & Warén, 1979 (extant flag source)
Anekes Bouchet & Warén, 1979 (basis of record)
Anidolyta Willan, 1987 (extant flag source)
Anidolyta Willan, 1987 (basis of record)
Anisodoris Bergh, 1898 accepted as Diaulula Bergh, 1878 (extant flag source)
Anisodoris Bergh, 1898 accepted as Diaulula Bergh, 1878 (basis of record)
Anodontia Link, 1807 (basis of record)
Ansates G. B. Sowerby II, 1839 accepted as Patella Linnaeus, 1758 (basis of record)
Antemnella Rankin, 1979 accepted as Asperspina Rankin, 1979 (basis of record)
Antemnella Rankin, 1979 accepted as Asperspina Rankin, 1979 (extant flag source)
Antonietta Schmekel, 1966 (extant flag source)
Antonietta Schmekel, 1966 (basis of record)
Aperiovula Cate, 1973 accepted as Pseudosimnia Schilder, 1927 (basis of record)
Aperiovula Cate, 1973 accepted as Pseudosimnia Schilder, 1927 (extant flag source)
Archidoris Bergh, 1878 accepted as Doris Linnaeus, 1758 (extant flag source)
Archidoris Bergh, 1878 accepted as Doris Linnaeus, 1758 (basis of record)
Arctica Schumacher, 1817 (basis of record)
Arctinula Thiele, 1934 accepted as Similipecten Winckworth, 1932 (extant flag source)
Arctinula Thiele, 1934 accepted as Similipecten Winckworth, 1932 (basis of record)
Arculus Monterosato, 1909 (basis of record)
Arculus Monterosato, 1909 (extant flag source)
Argonauta Linnaeus, 1758 (basis of record)
Armina Rafinesque, 1814 (basis of record)
Armina Rafinesque, 1814 (extant flag source)
Aspella Mörch, 1877 (basis of record)
Asperarca Sacco, 1898 (basis of record)
Asperspina Rankin, 1979 (extant flag source)
Asperspina Rankin, 1979 (basis of record)
Astarte J. Sowerby, 1816 (basis of record)
Asthelys Quinn, 1987 (extant flag source)
Asthelys Quinn, 1987 (basis of record)
Atagema Gray, 1850 (basis of record)
Atagema Gray, 1850 (extant flag source)
Atomiscala de Boury, 1909 (extant flag source)
Atomiscala de Boury, 1909 (basis of record)
Auriculigerina Dautzenberg, 1925 (extant flag source)
Auriculigerina Dautzenberg, 1925 (basis of record)
Auriculinella Tausch, 1886 (extant flag source)
Auriculinella Tausch, 1886 (basis of record)
Axelella Petit, 1988 (basis of record)
Axinodon Verrill & Bush, 1898 (basis of record)
Axinodon Verrill & Bush, 1898 (extant flag source)
Axinopsida Keen & Chavan in Chavan, 1951 (basis of record)
Axinus J. Sowerby, 1821 (basis of record)