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 environment
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/.