Light (A, B) and scanning electron (C-I) micrographs of Scutiglypha crenulata. (A) View of many specimens to illustrate variability in shape and size of the shell. (B-D) Lateral view of three specimens to illustrate general shape, symmetrical arrangement of shell plates and disposition of spines. (E) Apertural view. (F) Lateral view of apertural region to illustrate shape and arrangement of apertural-plates. (G) Close up view of apertural-plates. (H) Detail of shell surface to show characteristic scutiform and crenulated shell-plates. (I) View of modified shell-plate with spine.