Diverse groups of flagellates contain elongate species with 2 unequal (heterodynamic) flagella, including the cryptomonads, euglenids, kinetoplastids, and retortamonads. The unadorned surface of the flagella of organism we have described, distinguishes it from the cryptomonds and euglenids which have hairs on the flagella, and from the retortamonds which have lamellae on the flagella. Furthermore, the flagellum of kinetoplastids has a unique paraflagellar rod, the presence of which may have been indicated in the Moina flagellate by the longitudinal ridges (as shown in Fig. 2g).