living organisms
 see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
  
 Superkingdom Eukaryotae
 see Domain Eukaryota Chatton, 1925
    
 Kingdom Animalia Linnaeus, 1758 - animals
      
 Subkingdom Eumetazoa Butschli, 1910
 see [unranked] Eumetazoa Bütschli, 1910
        
 Phylum Mollusca Linnaeus, 1758 - molluscs
          
 Class Gastropoda Cuvier, 1795 - snails and slugs
            
 Subclass Opisthobranchia Milne-Edwards, 1848 - opisthobranchs
 see Order Opisthobranchia Milne-Edwards, 1848
              
 Order Runcinoidea Adams & Adams, 1854
 see Suborder Cephalaspidea Fischer, 1883
                
 Family Runcinidae Adams & Adams, 1854
                  
 Genus Runcina Forbes, 1851
                    
 1 Runcina coronata (Quatrefages, 1844)
                    
 2 Runcina setoensis Baba