Light microscope images of Cepedea longa. (A) Overview of the living specimens, to show general form, greatly elongated and cylindrical, with the anterior extremity broader and the posterior end pointed. Scale bar = 100 μm. (B) Living specimens, to show C. longa thickly flagellated and often coils when swimming. Scale bar = 100 μm. (C)–(D) Living specimens, to show body surface twisting and giving a spiral appearance. Scale bar = 50 μm. (E) Specimens stained with ammoniacal silver, to show the falx (arrow) and somatic kineties branching off from each side. Scale bar = 25 μm. (F) Specimens stained with silver nitrate, to show somatic kineties follow a sigmoid course from anterior to posterior end of the cell. Scale bar = 25 μm. (G) Specimens stained with ammoniacal silver, to show the organism possessing a large amount of spherical or ellipsoidal nuclei (arrow). Scale bar = 25 μm.