Phylum: Charophyta   Family: Desmidiaceae

Xanthidium impar (J.P. Jacobsen) Deflandre 1929

A rare desmid found in acidic to bordering on neutral waters. John, et al. (2011, p. 733, pl. 17: E) recorded it in Scottiish lochs and in the west of Ireland, but without details. The species has been observed several times with secondary short spines.

References: 
John, D.M., Whitton, B.A. & Brook, A.J. (2011 second edition) The Freshwater Algal Flora of the British Isles.
John, D.M. & Williamson, D.B. (2009) A Practical Guide to the Desmids of the West of Ireland.