Clearwater. 1 Stauroneis gracilis (6276) 2, 3 Stauroneis amphicephala (6277) 4 Stauroneis neohyalina (6277) 5 Stauroneis acidoclinata (6279) 6 Frustulia saxonica (6276) 7–9 Mastogloia elliptica (6280) 10 Halamphora sp., 11 Halamphora borealis (6280) 12–14 Navicymbula pusilla [Encyonema sp.? PH] (6280). Scale bar: 10 µm.