Light (A) and scanning electron (B-I) micrographs of Arcella bathystoma. (A-B) View of several specimens showing general shape of the shell. (C, D) Apertural view of two specimens to show deeply invaginated and comparatively large aperture. (E) Dorsal view showing regular depressions on aboral shell surface. (F) Lateral view. (G) Close up view of aperture to show apertural lip and surrounding large pores. (H, I) Portion of shell surface showing arrangement of the organic alveoli and regular depressions on the aboral surface of the shell.

  Part of: Todorov M, Bankov N (2019) An Atlas of Sphagnum-Dwelling Testate Amoebae in Bulgaria. Advanced Books.