This
biological division contains the algal
species Euglena and close to 1,000
species of related
algae; they are all
unicellular (single-celled) and are mainly found in
freshwater environments.
They are all photosynthetic (though some are secondary heterotrophs) and they all contain chlorophylls a and b. A unique feature of this division is that they store the energy they produce from photosynthesis as paramylum, an unusual carbohydrate (specifically, a glucose polymer) that is stored directly in the cell's cytoplasm. Members of this division have a contractile vacuole and a single flagellum.
From the science dictionary at http://biotech.icmb.utexas.edu/.