[Class] Polycystinea Ehrenberg, 1838 - polycystines see Superclass Polycystinia Ehrenberg, 1838 Order Nassellaria Ehrenberg, 1875 see Class Nassellaria Ehrenberg, 1847 Family Theoperidae Haeckel, 1881 Genus Eucyrtidium Ehrenberg, 1847 †Eucyrtidium hexacolum (Haeckel, 1887)