Phylum Foraminifera d'Orbigny, 1826 see Subphylum Foraminifera d'Orbigny, 1826
   Class Miliolata Saidova, 1981 - porcelaneous foraminifers
     Subclass Miliamminana Mikhalevich, 1980
       Order Schlumbergerinida Mikhalevich, 1980
         Family Sigmoilopsidae Vella, 1957
           Subfamily Sigmoilopsinae Vella, 1957
             Genus Sigmoilopsis Finlay, 1947
               1 Sigmoilopsis schlumbergeriᵀ (Silvestri, 1904)
               2 Sigmoilopsis procericollis Mikhalevich, 1977
               3 Sigmoilopsis arenata (Cushman, 1921)
               4 Sigmoilopsis flintii (Cushman, 1946)