[Class] Polycystinea Ehrenberg, 1838 - polycystines see Superclass Polycystinia Ehrenberg, 1838 Order Spumellaria Ehrenberg, 1875 see Class Spumellaria Ehrenberg, 1875 Family Spongodiscidae Haeckel, 1862 Genus Stylotrochus Haeckel, 1862 †Stylotrochus nitidus Sanfilippo & Riedel, 1973