Phylum Mollusca Linnaeus, 1758 - molluscs
   Class Gastropoda Cuvier, 1795 - snails and slugs
     Subclass Prosobranchia Milne-Edwards, 1848 - prosobranchs see Class Gastropoda Cuvier, 1795
       Order Caenogastropoda Cox, 1960 see Superorder Caenogastropoda Cox, 1960
         Superfamily Rissooidea Gray, 1847
           Family Megalomastomidae Blanford, 1864 see Family Megalomastomatidae Blanford, 1864
             01 Genus Megalomastoma Swainson, 1840
             02 Genus Aperostoma Troschel, 1847
             03 Genus Cyclojamaicia Bartsch, 1942
             04 Genus Cyclopilsrya Millard, 1996, orth. inval. see Genus Cyclopilsbrya Bartsch, 1942
             05 Genus Cyclovéndreysia Millard, 1996, orth. inval. see Genus Cyclovendreysia Bartsch, 1942
             06 Genus Farcimen Troschel, 1847
             07 Genus Farcimoides Bartsch, 1942
             08 Genus Liracyclotus Bartsch & Morrison, 1942
             09 Genus Tomocyclus Crosse & Fischer, 1872
             10 Subfamily Hainesiinae Thiele, 1929 see Family Megalomastomatidae Blanford, 1864