Haeckel, 1860
Four strongly compressed main spicules with large, wing-like latticed apophyses forming solid, centrally somewhat concave, meshwork. Sixteen secondary spicules short, forming delicate mesh with their apophyses. Main spicules with 8 pairs of myonemes; secondary with 5-6 pairs. Cell body quadrangular. Shell: 0.42 mm; cell body: 0.18 mm; length of main spicules: 0.21 mm, tropical spicules: 0.12-0.13 mm, polar spicules: 0.09 mm.