Spicules 2 times longer than external shell diameter, cylindrical, tapering to sharp tips, usually of equal size and shape; their basal ends provided with small pyramids which coalesce into spherule in center of the shell. Outer shell spherical to ellipsoidal, 2.5-3 times larger than internal spherical shell. Two aspinal pores oval elongate or reniform, very variable in shape and size. Coronal and sutural pores elongated, irregular. Diameter of external shell: 0.08-0.09 mm, internal: 0.03-0.035 mm; spicule length: 0.17 mm.