About Steromphala cineraria (Linnaeus, 1758)
The shell of Steromphala cineraria ranges in size from 12 mm to 18 mm. This shell is thick, narrowly umbilicate, and only rarely imperforate, with a thick conical shape. Its base color is ash-gray, and it is densely marked with many narrow longitudinal brown or reddish lines, or broader stripes. The shell has 6 flattened whorls. The upper surface of the body whorl has 7 or 8 thread-like spiral ridges, and there is often one or two finer striae between each ridge; the underside of the body whorl has around a dozen fine ridge-like striae. The body whorl is angulate at its periphery, and is somewhat convex on the underside. The aperture is subrhomboidal and smooth on the inside. The middle of the columella is straightened. The umbilicus is narrow. This species is distributed in the North Sea, the Mediterranean Sea, and the Atlantic Ocean off the coasts of the Azores, Canary Islands, and Morocco.
