Haeckel, 1887
Main spicules conical, tapering distally, ending in blunt tips. Four primary spicules 2 times longer and 3 times thicker than sixteen secondary; latter strongly compressed, with sharp tips. Polar spicules sometimes shorter than tropical. Cruciform leaf-cross especially well developed on equatorial and tropical spicules, forming large leaf-star almost filling central capsule. Length of main spicules: 0.15-0.20 mm; secondary: 0.09-0.10.