Trivellona abyssicola (M.M. Schepman, 1909)
Archierato accola (FOSSIL) (C.R. Laws, 1935 †)
Dolichupis acutidentata (J.S. Gaskoin, 1836)
Gregoia aemula D. Fehse, 2015
Trivellona aequabilis Fehse, 2017
Ellatrivia aequiflora (FOSSIL) (C.R. Laws, 1941 †)
Erato africana D. Fehse, 2016
Niveria africana (F.A. Schilder, 1931)
Dolichupis akangus L.R.L. Simone & C.M. Cunha,2012
Trivirostra akroterion (C.N. Cate, 1979)
Gregoia albamargarita D. Fehse, 2015
Gregoia albengai D. Fehse, 2015
Erato albescens W.H. Dall, 1905
Pusula alienigena (FOSSIL) F.A. Schilder, 1928 †
Trivellona aliquando D. Fehse, 2015
Gregoia alta Fehse, 2017
Alaerato amamioshima C.N. Cate, 1977
Triviella amaryllis F.A. Schilder, 1927
Cleotrivia andreiae Fehse & Grego, 2017
Alaerato angistoma (G.B. II Sowerby, 1832)
Niveria angliae (W. Wood, 1848)
Niveria anglioaffinis (F. Sacco, 1894)
Trivirostra angulata Fehse, 2017
Alaerato angulifera (G.B. II Sowerby, 1859)
Trivirostra angustata Fehse, 2017
Trivia annulata Unknown Author
Cleotrivia antillarum (F.A. Schilder, 1922)
Archierato antiqua (FOSSIL) (Marshall 1919 †)
Trivia antiquosphaera (FOSSIL) W.J. Broderip 1837 †
Triviella aperta (W.J. Swainson, 1822)
Trivia arctica (R. Pulteney, 1799)
Trivia arctica burdigalensis (FOSSIL) (A.V.M.D. D'Orbigny,1852 †)
Gregoia ariejansseni Fehse, 2017
Dolichupis artema (C.N. Cate, 1979)
Cleotrivia atomaria (W.H. Dall, 1902)