Euglena are a common group of unicellular protists, of the class Euglenoidea of the phylum Euglenophyta. They are single-celled organisms. Currently, over 1000 species of Euglena have been described. Marin et al. (2003) revised the genus to include several species without chloroplasts, formerly classified as Astasia and Khawkinea. Euglena sometimes can be considered to have both plant and animal features.
http://en.wikipedia.org/wiki/Euglena
