Description: The cells are (10)–12–18–(20) times longer than wide with truncated ends. The sides are repeatedly flatly undulated. The central cut is little formed. On both sides around the cut runs a ring with tiny, broadly rounded nipples. The cell wall is delicately punctured.

Dimension: Length (165)–200–250–(300) µm, width (10)–12–16–(18) µm.

Occurrence: Acidophilic alga, in acidic fens together with Micrasterias jenneri, Micrasterias truncata and Euastrum armatum.
Ubiquitous.

Left: Original graphic by Prof. Lenzenweger.
Right: Photomicrograph by Prof. Lenzenweger. For microphotography, the microscope illumination was adjusted in such a way that as many features as possible that are important for species identification are prominently displayed.

Copyright by Prof. Rupert Lenzenweger, Ried im Innkreis, Austria.