Class Crustacea Brünnich, 1772 - crustaceans see Superclass Crustacea Pennant, 1777
   Subclass Branchiura Thorell, 1864 - fish lice
     Order †Cyclida Schram, Vonk & Hof, 1997, nom. corr.
       Family †Halicynidae Gall & Grauvogel, 1967, nom. corr.
         Genus †Halicyne von Meyer, 1844
           †Halicyne laxa (Meyer, 1838)