Phylum: Charophyta   Family: Gonatozygaceae

Gonatozygon brebissonii A. De Bary 1858

First described and illustrated by De Bary (1858: 28, 77, pl. 4: 26, 27). The main distinguishing feature of this species is the cylindrical central region, attenuating to capitate apices.
Cell dimensions: L: 100-270 µm; B: 6-9 µm; L/B: 10-35.
Widely distributed in north-west Scotland in loch margins and boggy pools.

References: 
Brook, A.J. & Williamson, D.B. (2010) A Monograph on some British Desmids.
Coesel, P.F.M. & Meesters, K.J. (2023 second edition) Desmids of the Lowlands.
De Bary, A. (1858) Untersuchungen über die Familie der Conjugaten (Zygnemeen und Desmidieen) Ein Beitrag zur physiologischen und beschreibenden Botanik.
Ruzicka, J. (1977) Die Desmidiaceen Mitteleuropas, Volume 1, Part 1.
West, W. & West, G.S. (1904) A Monograph of the British Desmidiaceae, Volume 1.