SEM pictures of Sonderia vorax . A, B, D, General morphology. C, E, F. Particulars. A. Ventral view. The oral ciliature arises from and is in continuity with the somatic ciliature. B. Dorsal view. C. On the ventral cell side, the densely packed single ciliary rows with a membranelle-like appearance at higher magnification. Ectosymbiotic bacteria cover cell surface. D. Lateral view of a specimen with putative ejected longer type extrusomes. E. Detail of the surface showing the arrangement of ectosymbiotic bacteria in parallel rows between kineties. F. The striated band not covered by bacteria at higher magnification. The ridge-like lamellae are visible. Abbreviations: am, ciliary rows with a membranelle-like appearance; eb, ectosymbiotic bacteria; exI, longer type extrusomes; oc, oral ciliature; oo, oral opening; sc, somatic ciliature. Scale bars = 10 μm (A, B, D, E), 1 μm (C, F).