(Popofsky, 1904)
Skeleton with 1 main and 19 secondary spicules. Main spicule 0.2-0.5 mm longer than others, lance-shaped, 4-winged, edges smooth. Secondary spicules equal in length, 4-winged, 2 opposed edges smooth, other 2 serrated. Length of main spicule: 0.25-0.44 mm, secondary: 0.2-0.26 mm; cell body: 0.08-0.13 mm.