Transmission electron micrographs (TEM) of Auranticordis quadriverberis n. gen. et sp. A. Low magnification view showing the main cellular components: black bodies (b), nucleus (N), pale orange bodies (putative primary endosymbionts, PE), a degraded PE (double arrowhead) surrounded by sac-like vesicles (asterisk), surface ridges (arrows), and the ventral depression (vd) (Bar = 10 μm). B. Section through the surface showing a row of muciferous bodies (arrowheads) containing (orange) amorphous material. Each muciferous body is about 500–900 nm in diameter (Bar = 0.5 μm). C. High magnification view of muciferous bodies (arrowheads) and secreted mucus (arrow) (Bar = 0.5 μm). D. Section through the anterior region of the cell showing black bodies (b), the flagellar pocket (double arrowhead), four flagella (arrows), a nucleolus (n), a pointed nucleus (N), and the ventral groove (gr) (Bar = 5 μm). E. High magnification section through the surface ridges (arrow) showing underlying microtubules (arrowhead) and muciferous bodies (double arrowheads) (Bar = 0.5 μm). An inset showing a magnified view of a surface ridge (arrow) with a row of microtubules underneath (arrowhead) (Bar = 0.5 μm). F. Transverse section showing all four flagella within a flagellar pocket (arrowhead) near the nuclear anterior projection (N) (Bar = 1 μm).