Haecker
Diagnosis: Large, thick-walled spherical (rarely ellipsoidal) shell, with small (about 2-3 times bar width) circular or subcircular to subpolygonal pores, often partially framed, wide bars. Circular mouth, with thick rim, elevated as a collar- or crater-like structure. Short (2/3 shell diameter) main-spines. Numerous short (2 times pore diameter) by-spines.
Diameter: 0.9-1.3 mm.