Anterior spicule very different from others, with two equal, strongly divergent, bent horns. Lateral spicules little smaller, but with two very unequal horns (anterior shorter than posterior). Posterior spicule simple, sword-like or triangular, two-edged, longer than anterior spicule. Eight tropical spicules different, four anterior smaller, with longer horns; four posterior broader, with shorter horns; anterior horn of each tropical spicule longer than posterior. Eight polar spicules rudimentary, simple, very short. Length of equatorial cross: 0.6 mm, breadth: 0.4 mm.