Müller, 1856
Spicules 4-edged in cross section, tapering distally, linked in cell center by edges of small 5- or 6-edged pyramidal bases. Cell body spherical or polygonal, with numerous green zooxanthellae, yellow, red, or brownish pigment grains, and purple-red oil globules. Each spicule with 16-32 myonemes. Ectoplasm single-layered. Diameter of cell body: 0.17 mm; spicule length: 0.27-0.3 mm.