Light (A, B) and scanning electron (C-I) micrographs of Sphenoderia labiata. (A-C) View of many specimens to illustrate variability in shape and size of the shell. (D-F) Broad lateral view of three individuals to illustrate general shape and regular arrangement of shell-plates. (G) Close up view of aperture to illustrate shape and arrangement of apertural-plates and structure of the collar. (H) Detail of aboral region to show smaller, oval or circular shell-plates on the shell apex. (I) Detail of shell surface to show overlapping, oval shell-plates.