(Haeckel)
Central part of spider web-like skeleton is an hexagonal ring whose vertices support 6 radiating spines; 3 additional radial spines (dorsal and 2 main lateral) merge in center of hexagon. All spines produce rather regularly spaced anastomosing lateral branches. Diameter of central hexagon: ca. 40 µm.
Ref.: Petrushevskaya (1971a).