|  Genus: 
Two flagella with unequal length emerging from anterior canal, longer one directed anteriorly and held straight 
during swimming, shorter one curving laterally; cell body colorless, no eyespot, rigid, solitary, 
cylindrical, usually unflattened, one or more longitudinal lines or grooves present; 
hyaline inclusion in posterior half of the cell; freshwater and marine (Illustrated guide, 1985). Species:
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