(Müller, 1858)
Spicules equal in size and shape, 4-winged, tips sharp, from their basal third arise 4 short opposed apophyses; each with 40-60 myonemes. Basal leaf-star very large. Cell body spherical, central capsule red-brown. Diameter of cell body: 0.14 mm; length of spicules: 0.45-0.8 mm, width at base: 0.009-0.016 mm, at level of apophyses: 0.009-0.012 mm; length of basal leaf-star: 0.024-0.028 mm.