Haecker
Diagnosis: Thin-walled shell, weakly polyhedral, with subcircular to oval pores, about 3-6 times bar width, wide bars. Wide mouth, with a few main-spines. Main-spines on pyramids of 3-4 bars, simple, forked or weakly branched at the tips. By-spines about as long as pore width.
Diameter: 0.7-0.8 mm.