Phylum: Charophyta   Family: Zygnemataceae

Mougeotia scalaris A.H. Hassall 1842

First described by Hassall (1842: 45). A cosmopolitan species in North American and western Europe but not common. There are little data from England and Wales and none for Scotland. The zygospore is globose to slightly subglobose.
Cell dimensions: L: 50-150 µm, B: 20-35 µm.
Zygospore: 30-40 µm.
The current find was from a stream-feed to a loch.

References: 
Hassall, A.H. (1842). Observations on the genera Zygnema, Tyndaridea, and Mougeotia with descriptions of new species.
John, D.M., Whitton, B.A. & Brook, A.J. (2011 second edition) The Freshwater Algal Flora of the British Isles.