Haeckel
Diagnosis: Very thick-walled spherical, yellowish shell, with small (most about 2 times bar width) circular pores. Hexagonal pore frames result in funnel-shaped pores. Small (about 2 times pore diameter), circular mouth, surrounded by a ring of ordinary spines. Spines of variable size (to about 2 times pore diameter), but not differentiated into main- and by-spines.
Diameter: 0.55-1.0 mm.