Light (A) and scanning electron (B-I) micrographs of Sphenoderia minuta. (A-C) View of several specimens to illustrate variability in shape and size of the shell. (D, E) Broad lateral view of two induviduals to illustrate arrangement of shell-plates on the shell surface. (F) Narrow lateral view. (G) View of apertural region. (H) Close up view of aperture to illustrate shape and arrangement of apertural-plates and structure of the collar. (I) Detail of shell surface to show overlapping shell-plates.