Light (A, B) and scanning electron (C-I) micrographs of Playfairina valkanovi. (A, B) View of many specimens to illustrate variability in shape and size of the shell. (C-E) Broad lateral view of four specimens showing general shape. (F) Latero-apertural view(G) Broad lateral view of apertural region to show evaginated collar, composed of two rows small and prolonged plates. (H) Close up view of aperture illustrating its oval shape and surrounding denticulate apertural-plates, each of them with sharp median tooth. (I) Detail of shell surface showing arrangement of shell-plates.