(Haeckel, 1887)
Spicules 4-bladed, pyramidal, tapering gradually from base toward distal end. Ectoplasm finely granulated. Few (6-8) zooxanthellae. Each spicule surrounded by 8 pear- or egg-shaped myonemes. Ectoplasmic cortex 2-layered. Cell body diameter: 0.1 mm, spicule length: 0.14 mm.