Joculator abbreviatus (K.H.J. Thiele, 1930)
Clathropsis abelai A. Cecalupo & I. Perugia,2014
Cerithiopsis abjecta H.B. Preston, 1905
Marshallopsis aboreensis Cecalupo & Perugia, 2017
Cerithiopsis abreojensis P. Bartsch, 1911
Cerithiopsis abruptum R.B. Watson, 1880
Dizoniopsis abylensis P. Bouchet, S. Gofas& A. Warén, 2010
Cerithiopsis academicorum E. Rolán & J. Espinosa,1996
Aliptina acheronae B.A. Marshall, 1978
Cerithiopsis acicula Š. Brusina, 1864
Cerithiopsis acontium W.H. Dall, 1889
Synthopsis acuminata B.A. Marshall, 1978
Joculator acuminatus A. Cecalupo & I. Perugia,2012
Horologica acuta A. Cecalupo & I. Perugia,2013
Clathropsis acutissima A. Cecalupo & I. Perugia,2013
Cerithiopsina adamsi (P. Bartsch, 1911)
Seila adamsii (H.C. Lea, 1845)
Cerithiopsis adelpha J.C. Melvill & R. Standen,1896
Joculator aeneus Cecalupo & Perugia, 2017
Cerithiopsis aequatorialis K.H.J. Thiele, 1925
Cerithiopsis aequicincta (FOSSIL) H.H. Suter, 1917 †
Horologica affinis A. Cecalupo & I. Perugia,2012
Cerithiopsis agulhasensis (K.H.J. Thiele, 1925)
Cerithiopsis aimen E. Rolán & J. Espinosa,1996
Cerithiopsis alabastrula (O.A.L. Mörch, 1876)
Prolixodens alba Cecalupo & Perugia, 2017
Synthopsis albachiarae A. Cecalupo & I. Perugia,2012
Marshallopsis albachiarae A. Cecalupo & I. Perugia,2012
Synthopsis albatros A. Cecalupo & I. Perugia,2014
Marshallopsis albicans A. Cecalupo & I. Perugia,2012
Horologica albino C.F. Laseron, 1956
Joculator albocinctum (J.C. Melvill & R. Standen,1896)
Joculator albordina C.F. Laseron, 1956
Synthopsis albostriata A. Cecalupo & I. Perugia,2013
Seila albosutura (J.E. Tenison-Woods,1876)