Cerithiopsis apicicosta W.L. May, 1920
Socienna apicicostata (W.L. May, 1919)
Cerithiopsis apicina W.H. Dall, 1927
Cerithiopsis aquilum H.A. Rehder, 1980
Dizoniopsis aquitaniensis (FOSSIL) (A.E.M. Cossmann& M.A. Peyrot, 1922 †)
Cerithiopsis ara W.H. Dall & P. Bartsch,1911
Cerithiopsis aralia A.A. Olsson & A. Harbison,1953
Horologica arbastoi A. Cecalupo & I. Perugia,2013
Clathropsis arcangelae Cecalupo & Perugia, 2017
Joculator arduinii A. Cecalupo & I. Perugia,2012
Joculator arenaceus A. Cecalupo & I. Perugia,2013
Cerithiopsis arga E.A. Kay, 1979
Cerithiopsis argentea W.H. Dall, 1927
Cerithiopsis arnoldi P. Bartsch, 1911
Dizoniopsis aspicienda P. Bouchet, S. Gofas& A. Warén, 2010
Seila assimilata (C.B. Adams, 1852)
Cerithiopsis atalaya R.B. Watson, 1885
Joculator ater A. Cecalupo & I. Perugia,2012
Clathropsis atimovatae A. Cecalupo & I. Perugia,2014
Marshallopsis atrata A. Cecalupo & I. Perugia,2012
Synthopsis attenuata A. Cecalupo & I. Perugia,2012
Seila attenuata C. Hedley, 1900
Seila attenuissima (FOSSIL) P. Marshall & R. Murdoch,1920 †
Cerithiopsis aurantiaca J.C. Melvill & R. Standen,1896
Cerithiopsis aurea P. Bartsch, 1911
Joculator autumnus Cecalupo & Perugia, 2016
Cerithiopsis baculum A. Adams, 1861
Cerithiopsis bakeri P. Bartsch, 1917
Cerithiopsis balaustium R.M.A. Figueira& A. Pimenta, 2008
Belonimorphis ballardi A. Cecalupo & I. Perugia,2013
Horologica balteata (R.B. Watson, 1881)
Sundaya bancheti Cecalupo & Perugia, 2017
Seila bandorensis (J.C. Melvill, 1893)
Joculator baraggiai A. Cecalupo & I. Perugia,2013
Mendax barbarae Cecalupo & Perugia, 2017