[Kingdom] Animalia Linnaeus, 1758 - animals
   Grade Enterozoa
     Grade Cœlomata
       Phylum Mollusca Linnaeus, 1758 - molluscs
         Branch Eucephala
           Grade Echinoglossa
             Class Gastropoda Cuvier, 1795 - snails and slugs
               Grade Cochlides
                 Order Cryptocochlides
                   Genus Aplysia Linnaeus, 1767 - seahare