(Müller, 1858)
Spicules thin, two-edged or quadrangular-prismatic, same diameter from base to origin of apophyses. Delicate lattice shell spherical, with very large subcircular to irregularly polygonal pores with thin bars. Basal ends of spicules form a central mass. Sutures give rise to short, smooth accessory spines. Diameter of sphere: 0.11 mm; spicule length: 0.11 mm.