[Kingdom] Animalia Linnaeus, 1758 - animals
   Grade Enterozoa
     Grade Cœlomata
       Phylum Mollusca Linnaeus, 1758 - molluscs
         Branch Eucephala
           Grade Echinoglossa
             Class Cephalopoda Cuvier, 1795 - cephalopods
               Grade Siphonopoda
                 Order Dibranchia
                   1 Genus Spirula Lamarck, 1799
                   2 Genus Loligo Lamarck, 1798 - long-finned squid