Light (A, C) and scanning electron (B, D-I) micrographs of Cyphoderia major. (A-C) View of many specimens to illustrate variability in shape and size of the shell. (D, E) Apertural view of two individuals to show general shape and regular arrangement of shell-plates. (F) Dorsal view. (G) Lateral view of C. ampulla and C. major showing differences in their shell structure and size. (H) Close up view of aperture to illustrate its circular shape and arrangement of numerous denticulate apertural-plates. (I) Detail of shell surface to show regular arrangement of shell-plates.