Heikea pulchra (FOSSIL) Isberg, 1934 †
Cyrtodontula quadrangularis (FOSSIL) R.P. Whitfield †
Cyrtodonta quartzitica (FOSSIL) Frech, 1891 †
Cyrtodontula radiata (FOSSIL) (C.C. Stewart, 1920 †)
Heikea rara (FOSSIL) Isberg, 1934 †
Pharcidoconcha raupi (FOSSIL) Pojeta& Gilbert-Tomlinson, 1977 †
Heikea reniformis (FOSSIL) Isberg, 1934 †
Cyrtodonta richardi (FOSSIL) Isberg, 1934 †
Cyrtodonta rotulata (FOSSIL) Ulrich, 1894 †
Heikea rotunda (FOSSIL) Isberg, 1934 †
Vanuxemia rotundata (FOSSIL) J.W. Hall †
Cyrtodontula rugatina (FOSSIL) (Ulrich, 1892 †)
Cyrtodonta rugosa (FOSSIL) Billings, 1858 †
Heikea saffordi (FOSSIL) Isberg, 1934 †
Vanuxemia sardesoni (FOSSIL) Ulrich, 1894 †
Cyrtodonta scala (FOSSIL) W.J. Raymond, 1906 †
Cyrtodonta schmalenseei (FOSSIL) Isberg, 1934 †
Cyrtodontula scofieldi (FOSSIL) (Ulrich, 1890 †)
Cyrtodonta securiformis (FOSSIL) (Portlock) †
Cyrtodontula securiformis (FOSSIL) (Foerste, 1914 †)
Heikea selecta (FOSSIL) Isberg, 1934 †
Cyrtodontula sigmoidea (FOSSIL) (Billings, 1858 †)
Cyrtodontula sohli (FOSSIL) Pojeta& Gilbert-Tomlinson, 1977 †
Cyrtodonta solitaria (FOSSIL) W.J. Raymond, 1905 †
Cyrtodonta staffordae (FOSSIL) Pojeta& Gilbert-Tomlinson, 1977 †
Cyrtodontula sterlingensis (FOSSIL) (F.B. Meek& A.H. Worthen, 1890 †)
Ortonella stewarti (FOSSIL) Foerste, 1924 †
Macrodesma striata (FOSSIL) Isberg, 1934 †
Cyrtodontula subcarinata (FOSSIL) (Ulrich, 1894 †)
Vanuxemia suberecta (FOSSIL) Ulrich, 1894 †
Heikea subglobosa (FOSSIL) Isberg, 1934 †
Cyrtodonta subovata (FOSSIL) Ulrich, 1894 †
Vanuxemia subrotunda (FOSSIL) Ulrich, 1894 †
Cyrtodontula subtruncata (FOSSIL) (J.W. Hall, 1847 †)
Cyrtodonta suecica (FOSSIL) Isberg, 1934 †