Phylum: Charophyta   Family: Mesotaeniaceae

Netrium elongatum S. Ohtani 1990

Ohtani (1990: 34, figs. 29-31). gives the habitat in Japan as abandoned paddy fields, ponds and marshes. He describes the cells attenuating from the centre, but his illustrations of larger cells show a parallel section before attenuating. My larger cells have this characteristic, which may be a result of the start of division. Cell dimensions are a combination of Ohtani’s and mine, which are very similar.
Cell dimensions: L: 190-329 µm; B: 47-65 µm, L/B: 3.5-6.5.
Recently found in the Outer Hebrides in mildly acidic habitats such as abandoned peat-cuttings and moorland bogs.

References: 
Ohtani, S. (1990). A Taxonomic Revision of the Genus Netrium (Zygnematales, Chlorophyceae).