[Class] Polycystinea Ehrenberg, 1838 - polycystines see Superclass Polycystinia Ehrenberg, 1838
   Order Spumellaria Ehrenberg, 1875 see Class Spumellaria Ehrenberg, 1875
     Family Actinommidae Haeckel, 1862
       Genus Hexacontium Haeckel, 1881
         01 Hexacontium arachnoidale Hollande, 1960
         02 Hexacontium aristarchi (Haeckel, 1887)
         03 †Hexacontium armatum/hostile group
         04 Hexacontium axotrias Haeckel, 1887
         05 Hexacontium enthacanthum Jørgensen, 1900
         06 Hexacontium gigantheum Cortese & Bjørklund, 1998
         07 Hexacontium heracliti (Haeckel, 1887)
         08 †Hexacontium hexactis (Stöhr, 1880)
         09 †Hexacontium hootsi Campbell & Clark, 1944
         10 Hexacontium hystricina (Haeckel, 1887)
         11 Hexacontium laevigatum Haeckel, 1887
         12 Hexacontium melpomene (Haeckel, 1887)
         13 Hexacontium pachydermum Jørgensen, 1900
         14 †Hexacontium palaeocenicum Sanfilippo & Riedel, 1973