About Tegula rustica (Gmelin, 1791)
The shell of Tegula rustica reaches 33 mm in height and 32 mm in diameter. This heavy, solid, umbilicate shell has a conical shape. Its color ranges from chocolate to brownish-olivaceous. The conical spire is more or less elevated, and the suture is distinctly impressed. There are 6 to 7 whorls that are moderately convex or nearly flat, sometimes swollen just below the sutures. These whorls are either smooth or have longitudinal folds, which are usually underdeveloped and only visible a short distance below the sutures. The shell has faint spiral grooves across its surface. The body whorl is obtusely angular at its periphery, and the base of the shell is nearly flat. The aperture is very oblique. The columella has one or two teeth near its lower end, and is expanded above into a white callus that partially surrounds the narrow, deep circular umbilicus. This marine species is found off the coast of Japan.
