[Kingdom] Animalia Linnaeus, 1758 - animals
   Grade Enterozoa
     Grade Cœlentera
       Phylum Nematophora Huxley, 1850
         Class Hydrocorallinæ Mosley
           Order Petrosa
             1 Genus Stylaster Gray, 1831
             2 Genus Millepora Linnaeus, 1758