Phylum: Chlorophyta   Family: Oedogoniaceae

Oedogonium undulatum  A. Braun ex Hirn 1900

A rare filamentous alga that was historically quite widely recorded. It prefers an acidic freshwater habitat.

References: 
ohn, D.M., Whitton, B.A. & Brook, A.J. (2011 second edition) The Freshwater Algal Flora of the British Isles.