Strophiops primigenia C.J. Maynard, 1913
Strophiops primordia C.J. Maynard & W.F. Clapp,1921
Strophiops prisca C.J. Maynard & W.F. Clapp,1915
Strophiops proavita C.J. Maynard & W.F. Clapp,1921
Cerion processum (C.J. Maynard & W.F. Clapp,1920)
Strophiops procliva C.J. Maynard & W.F. Clapp,1921
Strophiops profunda C.J. Maynard & W.F. Clapp,1921
Cerion prognata (C.J. Maynard & W.F. Clapp,1920)
Strophiops progressa C.J. Maynard & W.F. Clapp,1920
Cerion proteus J. Gundlach, 1860
Cerion pseudocyclostomum C.G. Aguayo& M.I. Sánchez Roig, 1953
Cerion pulla (C.J. Maynard & W.F. Clapp,1920)
Cerion pumilia (C.J. Maynard, 1894)
Cerion pupa P.F. Röding, 1798
Strophiops purpurea C.J. Maynard, 1913
Cerion pygmaeum H.A. Pilsbry & E.G. Vanatta,1896
Strophiops ralla C.J. Maynard & W.F. Clapp,1921
Cerion ramsdeni C. de la Torrein D.A. Welch, 1934
Cerion recessa (C.J. Maynard & W.F. Clapp,1919)
Strophiops rediviva C.J. Maynard, 1913
Cerion regina H.A. Pilsbry & E.G. Vanatta,1895
Cerion regina brevispira H.A. Pilsbry & E.G. Vanatta,1895
Cerion regina eucosmium H.A. Pilsbry & E.G. Vanatta,1895
Cerion regina percostatum H.A. Pilsbry & E.G. Vanatta,1895
Cerion regina swiftii H.A. Pilsbry & E.G. Vanatta,1895
Cerion regium W.H. Benson, 1841
Strophiops regula C.J. Maynard, 1894
Strophiops rehderi W.J. Clench & C.G. Aguayo,1952
Strophiops reincarnata C.J. Maynard & W.F. Clapp,1921
Cerion reliqua (C.J. Maynard & W.F. Clapp,1921)
Strophiops repetita C.J. Maynard & W.F. Clapp,1921
Strophiops restricta C.J. Maynard, 1894
Cerion reticulatum W.H. Dall, 1905
Strophiops rhyssum W.H. Dall, 1905
Cerion ricardi W.J. Clench & C.G. Aguayo,1951