Phylum Arthropoda Siebold, 1848 - arthropods
   Subphylum Crustacea Brünnich, 1772 - crustaceans see Superclass Crustacea Pennant, 1777
     Class Maxillopoda Dahl, 1956 see Subphylum Pancrustacea Zrzavý et al., 1997
       Subclass Pentastomida Diesing, 1836 - tongue worms
         Order Porocephalida Heymons, 1935
           1 Family Armilliferidae Fain, 1961
           2 Family Diesingidae Fain, 1961
           3 Family Linguatulidae Haldeman, 1851
           4 Family Porocephalidae Fain, 1961
           5 Family Sambonidae Fain, 1961
           6 Family Sebekiidae Fain, 1961
           7 Family Subtriquetridae Fain, 1961