FIG. 11 in A study of the morphology and distribution of four Achnanthidium Kütz. species (Bacillariophyta), implications for ecological status assessment, and description of two new European species

FIG. 11. — Achnanthidium neomicrocephalum Lange-Bert. & F.Staab, specimens from Lustsee, Germany: A-F, SEM views of rapheless valves; A, SEM external view of valve; B, SEM internal view of valve; C, SEM external view of pole; D, SEM external view of valve centre; E, SEM internal view of valve centre; F, SEM internal view of pole. Scale bars: A, B, 5 µm; C-F, 1 µm.