Genus Sexangularia Awerintzew, 1906
Diagnosis: Test organic, sometimes with attached mineral particles; cross-section polygonal, mostly hexagonal. Nucleus vesicular.
Sexangularia minutissima (Penard, 1904) Awerintzew, 1906
Raphidocystis arborescens (Jones 1974) Zlatogursky, 2018 Basionym: Cienkowskya arborescens Jones, 1974 Diagnosis: under construction Ecology:
after Zlatogursky et al., 2018 Raphidocystis glabra Dürrschmidt, 1985 Diagnosis: Periplast 40-50 μm in diameter; spine-scales 4.6–15 μm; plate-scales 6-7 × 3-3.5 μm; tiny teeth
Raphidocystidae Zlatogursky, 2018 Diagnosis: centrohelids with monolayered plate-scales covering cell surface. Plate-scales with a hollow inflected margin. Sometimes trumpet-shaped or tubular spine-scales present, forming an
P. liboica – from Bonnet, 1979 Planhoogenraadia liboica Bonnet, 1979 Diagnosis: . Test relatively flat, with a dorsal convexity. Shell widest in the center. Aperture deep
Deharvengia papuensis, after Bonnet, 1979 Deharvengia papuensis Bonnet, 1979 Diagnosis: Theca large, ovoid, very regular, colorless. Elliptical pseudostome bordered by a thick yellowish lip or