(Haeckel, 1887)
Apophyses of eight tropical spicules crossed by transverse beam, which is again crossed by two perpendicular branches; by union of these branches each tropical spicule forms square shield with four crossed pores and 12 to 16 marginal spikes. On base of each spicule (in surface of outer shell) four crossed aspinal pores which correspond to those of free shields; somewhat larger than other pores. Diameter of outer shell: 0.12 mm, of inner: 0.06 mm.