Shell ellipsoidal or spherical. Spicules strongly compressed, two-edged, narrowing gradually from middle toward each end; basal ends with conical structures which fuse into central spherule. Aspinal pores triangular or elongated, surrounded by 10-12 sutural pores, latter 3-4 times smaller than former. Shell surface with inconspicuous sutures, rough, with furrows, pustules or tiny thorns. Diameter of shell (without spicules): 0.08-0.1 mm; length of main spicules: 0.08-0.1 mm.