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 Nudibranchia Cuvier, 1814 - "true" nudibranchs
         Suborder Doridina Odhner, 1934
           Superfamily Anadoridoidea Vaught, 1989, nom. inval.
             Family Okeniidae Iredale & O'Donoghue, 1923 see Family Goniodorididae Adams & Adams, 1854
               Subfamily Okeniinae Iredale & O'Donoghue, 1923 see Family Goniodorididae Adams & Adams, 1854
                 1 Genus Okenia Menke, 1830
                 2 Genus Idaliella Bergh, 1881