[Class] Polycystinea Ehrenberg, 1838 - polycystines see Superclass Polycystinia Ehrenberg, 1838 Order Spumellaria Ehrenberg, 1875 see Class Spumellaria Ehrenberg, 1875 Family Spongodiscidae Haeckel, 1862 Genus Spongodiscus Ehrenberg, 1854 †Spongodiscus quartus (Borisenko, 1958) 1 Spongodiscus quartus bosoculus Sanfilippo & Riedel, 1973 2 †Spongodiscus quartus quartus (Borisenko, 1958)