Phylum: Euglenophyta   Family: Phacaceae

Lepocinclis tripteris (Dujardin) B. Marin & Melkonian

The specific epithet means three-winged referring to the appearance of three ridges. It can be locally common in circumneutral bogs, pools and ditches, but generally scarce

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