Obtusella isseli (G.W. Tryon, 1886)
Obtusella lata E. Rolán & F. Rubio, 1999
Obtusella macilenta (T.A. de M. Monterosato,1880)
Obtusella magna (J.H. Gatliff& C.J. Gabriel, 1911)
Obtusella orisparvi (FOSSIL) Moreno, A. Peñas& E. Rolán, 2003 †
Obtusella roseotincta (P. Dautzenberg, 1889)
Obtusella spina (J.C.H. Crosse& P.H. Fischer, 1864)
Obtusella trachealis (A.A. Gould, 1861)
Obtusella tumidula (G.O. Sars, 1878)
Obtusella urdeneta (P. Bartsch, 1917)
Omanimerelina eloiseae R.G. Moolenbeek & C. Bosch,2007
Onoba aculeus (Gould, 1841)
Onoba aedicula (FOSSIL) (C.R. Laws, 1940 †)
Onoba aedonis (R.B. Watson, 1886)
Onoba agnewi (J.E. Tenison-Woods,1877)
Onoba ainsworthi C. Hedley, 1916
Onoba alfredensis (P. Bartsch, 1915)
Onoba algida W.F. Ponder & H.W. Worsfold,1994
Onoba alpha (A.W.B. Powell, 1955)
Onoba amissa W.F. Ponder & H.W. Worsfold,1994
Onoba analoga A.W.B. Powell, 1937
Onoba anderssoni (H. Strebel, 1908)
Onoba antleri Güller & Zelaya, 2017
Onoba aupouria (A.W.B. Powell, 1940)
Onoba aurivillii (W.H. Dall, 1887)
Onoba australiae (G.R. von Frauenfeld,1867)
Onoba bakeri (P. Bartsch, 1910)
Onoba beta (A.W.B. Powell, 1955)
Onoba biangulata (FOSSIL) (C.R. Laws, 1936 †)
Onoba bickertoni (C. Hedley, 1916)
Onoba brachia (R.B. Watson, 1886)
Onoba breogani E. Rolán, 2008
Onoba brunnea A.N. Golikov& O.V. Kussakin, 1978
Onoba candidissima (W.H. Webster, 1905)
Onoba canfieldi W.H. Dall & P. Bartsch,1907
Onoba caribu Güller & Zelaya, 2017