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 Caecidae Gray, 1850 - caecids
             Subfamily Caecinae Gray, 1850
               01 Genus Caecum Fleming, 1813
               02 Genus Brochina Gray, 1857
               03 Genus Elephantellum Bartsch, 1920
               04 Genus Elephantulum Carpenter, 1857
               05 Genus Fartulum Carpenter, 1857
               06 Genus Meioceras Carpenter, 1859
               07 Genus Micranellum Bartsch, 1900
               08 Genus Pictocaecum Habe, 1978
               09 Genus Pseudoparastrophia Distaso, 1905
               10 Genus Strebloceras Carpenter, 1859
               11 Genus Watsonia de Folin, 1880