Borgert
Diagnosis: Shell usually nearly spherical, valves almost the same size, about hemispherical or tapering slightly aborally, rims sometimes slightly indented. Rims of both valves with strong, conical teeth of about the same length, about 10-15 on each side of each valve. Aboral rim widened into a lip- or nose-shaped structure, rounded or sometimes pointed. Pores circular, regularly arranged, about 2-3 times bar width. Bars smooth or weakly framed.
Length: 0.022-0.024 mm.