Teinostoma abditum E. Rolán, F. Rubio& P. Ryall, 2000
Teinostoma abnorme E.A. Smith, 1890
Tornus abyssicola K.J. Bush, 1897
Pseudoliotia acidalia (J.C. Melvill & R. Standen,1899)
Circulter acuta C.F. Laseron, 1958
Circulus acutilirata (K.H.J. Thiele, 1925)
Cyclostremiscus adamsi H.A. Pilsbry & A.A. Olsson,1945
Cochliolepis adamsii (P. Fischer, 1857)
Tornus aemilii E. Rolán & F. Rubio, 2002
Circulus aequatorialis (K.H.J. Thiele, 1925)
Teinostoma africanum E.A. Smith
Tornus africanus W. Adam & J. Knudsen,1969
Vitrinella aguayoi (J.X. Corgan, 1968)
Anticlimax aitormonzoi F. Rubio & E. Rolán, 2014
Cyclostremiscus albachiarae I. Perugia, 2015
Cochliolepis albicerata W.F. Ponder, 1966
Elachorbis albolapis (FOSSIL) C.R. Laws, 1930 †
Cochliolepis alfredensis (P. Bartsch, 1915)
Solariorbis allomphalus H.A. Pilsbry & A.A. Olsson,1952
Teinostoma altum H.A. Pilsbry, 1953
Teinostoma americanum H.A. Pilsbry & A.A. Olsson,1945
Solariorbis ametabolus H.A. Pilsbry & A.A. Olsson,1952
Teinostoma amplectans P.P. Carpenter, 1857
Teinostoma anastomosis F. Rubio, E. Rolán& Y.C. Lee, 2011
Cyclostremiscus anceps (FOSSIL) (C.R. Laws, 1941 †)
Teinostoma andrium (FOSSIL) W.P. Woodring, 1957 †
Naricava angasi (A. Adams, 1864)
Pseudoliotia anglypta (A. Adams, 1863)
Circulus angulata (C.B. Adams)
Naricava angulata (C. Hedley, 1905)
Anticlimax annae H.A. Pilsbry & A.A. Olsson,1950
Vitrinella anneliesae D. De Jong & H.E. Coomans,1988
Solariorbis annulatus (P.P. Carpenter, 1857)
Vitrinella annulifera (P. Dautzenberg, 1910)
Teinostoma anomala T. Iredale, 1936