Schröder
Diagnosis: Very thick spherical shell, with large circular to oval pores, 1-2 times bar width, framed. Circular mouth (about 3 times pore width) with 2 short conical main-spines. Main-spines fairly sparse, relatively short (about 4 times pore width), some slightly curved. By-spines long (about 3 times pore width) and slender.
Diameter: 0.7 mm.