(Haeckel, 1860)
Two main spicules cylindrical to very slightly compressed, linear, of equal breadth throughout whole length; apex emarginate or bifid; base with large leaf-cross of double breadth. Eighteen smaller spicules strongly flattened, two-edged, needle-like along narrow side, one-fourth to one-half as large. Central capsule ellipsoidal, yellow, pellucid. Length of 2 major spicules: 0.15 to 0.25 mm, breadth: 0.004 to 0.006 mm; length of 18 secondary spicules: 0.05 to 0.1 mm.