[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
         1 †Stylotrochus alveatus Sanfilippo & Riedel, 1973
         2 †Stylotrochus charlestonensis (Campbell & Clark, 1945)
         3 †Stylotrochus nitidus Sanfilippo & Riedel, 1973
         4 Stylotrochus quadribrachiatus Sanfilippo & Riedel, 1973
         5 †Stylotrochus sol Campbell & Clark, 1944