Hood. 1 Geissleria moseri (6898) 2, 3 Hygropetra balfouriana (6904) 4 Frustulia vulgaris (6913) 5 Frustulia crassinervia (6899, 6900, 6905) 6 Sellaphora sp. (6909) 7 Sellaphora rectangularis (6909) 8 Sellaphora pupula (6909) 9, 10 Sellaphora parapupula (6903, 6907, 6909) 11, 12 Amphora copulata (6908, 6912) 13 Muelleria bachmannii (6908) 14, 15 Diploneis arctica [D. ovalis ssp. arctica PH] (6907, 6908) 16 Diploneis parma (6908) 17 Kobayasiella micropunctata (6903, 6905) 18 Kobayasiella jaagii [K. micropunctata PH] (6907) 19 Decussata placenta (6898). Scale bars: 10 µm.