Light (A) and scanning electron (B-I) micrographs of Centropyxis spinosa. (A, B) View of many specimens to illustrate variability in shape and size of the shell. (C, D) Apertural view of two specimens to show general shape and shell structure. (E) Lateral view. (F) Latero-dorsal view. (G) Close up view of aperture showing its circular shape and smooth surface around the aperture. (H) Detail of posterior end of the shell to illustrate shape and structure of spines. (I) Detail of dorsal side of the shell showing its rough surface, covered mainly with flattish particles.