Light (A, B) and scanning electron (C-I) micrographs of Difflugia penardi. (A-C) View of many specimens to illustrate variability in shape and size of the shell. (D-E) Lateral view of two specimens showing rough surface of the shell. (F) Latero-apertural view. (G) Apertural view. (H) Close up view of aperture to show bordering small particles. (I) Portion of shell to illustrate arrangement of particles and rough surface of the shell.