(Haeckel)
Chinese peasant hat-like shell with a small cephalis. Thorax widely open, with small, regularly arranged pores, circular proximally and becoming larger and more polygonal distally, with 3 conspicuous symmetrical ribs (dorsal and main lateral spines). Abdominal brim flat, with 5-8 rows of very regular, quadrangular pores. Shell diameter: 130-300 µm.
Ref.: Haeckel (1887), Benson (1966).