[Class] Polycystinea Ehrenberg, 1838 - polycystines see Superclass Polycystinia Ehrenberg, 1838
   Order Nassellaria Ehrenberg, 1875 see Class Nassellaria Ehrenberg, 1847
     Family Plagiacanthidae Hertwig, 1879
       Genus Plectacantha Jørgensen, 1905
         1 †Plectacantha cremastoplegma Nigrini, 1968
         2 Plectacantha oikiskos Jørgensen, 1905
         3 Plectacantha trichoides Jørgensen, 1905