Radial spicules similar, 4-winged, smooth-edged, very thin, widening rapidly from base, outside soft parts equally wide to pointed distal ends. Basal spicule ends heart- or grape seed-shaped, fitted loosely in center. Cell body star-shaped, colorless; ectoplasm vacuolar. Two kinds of pseudopodia. Central capsule membrane lacking. Periplasmic cortex wide, structureless. Four to six very long thread-like myonemes. Shell diameter: 0.9-1.0 mm; cell body: 0.48-0.5 mm.