Phylum: Charophyta   Family: Desmidiaceae

Desmidium baileyi (J. Ralfs) O. Nordstedt 1880

First described and illustrated by Ralfs (1848: 208, pl. 35:1) as Aptogonum baileyi. It was later moved to Desmidium by Nordstedt (1880: 4). This species has bi-, tri- and quadri-radiate forms. The latter two forms have cell dimensions that are about as long as broad. The much rarer bi-radiate form is broader than long with dimensions that match D. aptogonum, but that species is consistently tri-radiate. (See AlgaeBase for identical images: https://www.algaebase.org/search/images/detail/?img_id=23475.)
Cell dimensions (for bi-radiate form): L: 19-22 µm; B: 26-30 µm.
A very rare species found in slightly acidic waters such of moorland bogs and pools, also shallow lochans.

References: 
Ralfs, J. (1848) The British Desmidieae.
Prescott, W.G. et al. (2001 reprint) A Synopsis of North American Desmids. Part II, Desmidiaceae: Placodermae, Section 5.
Nordstedt, C.F.O. (1880) De algis et Characeis 1. De algis nonullis, praecipue Desmidieis, inter Utricularias Musei Lugduno-Batavi.