Phylum: Euglenozoa   Family: Euglenidae

Monomorphina pyrum  (Ehrenberg) Mereschkowsky

Widespread in ditches, lochs and moorland pools. Can tolerate brackish water

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