[Class] Polycystinea Ehrenberg, 1838 - polycystines see Superclass Polycystinia Ehrenberg, 1838
   Order Nassellaria Ehrenberg, 1875 see Class Nassellaria Ehrenberg, 1847
     Family Trissocyclidae Haeckel, 1881 see Family Acanthodesmiidae Haeckel, 1862
       Genus Zygocircus Bütschli, 1881
         1 †Zygocircus buetschli Haeckel, 1887
         2 †Zygocircus cimelium Petrushevskaya, 1972
         3 Zygocircus piscicaudatus Popofsky, 1913
         4 Zygocircus productus (Hertwig, 1879)