About Phorcus mutabilis (R.A.Philippi, 1851)
This species is a sea snail scientifically named Phorcus mutabilis (R.A.Philippi, 1851). The shell of this species ranges in size between 12 mm and 24 mm. It is a solid, globose-conoid shell that is either umbilicate or subimperforate. It resembles a young individual of the species Phorcus articulatus. The shell is most often colored grayish-yellow, yellow, or flesh-tinted. It is marked more or less distinctly with obliquely radiating lines or maculations of dull crimson. These markings are sometimes broken into tessellations, and sometimes the shell is faintly and minutely marked with reddish articulations, making it appear nearly unicolored. The short spire is conoid in shape, and the suture is impressed. The shell has 5 to 6 whorls, which are slightly convex and finely spirally grooved. The body whorl is somewhat flattened across its upper portion. The large aperture is very oblique. The lip forms a half circle, and it is less thickened and less beveled on the interior than the lip of Phorcus articulatus. The columella is more flattened than the columella of Phorcus articulatus. It is barely edged with pearl, and its tooth or lobe is less heavy and more acute than the same structure in Phorcus articulatus. The umbilical region is always more deeply excavated than that of Phorcus articulatus. The umbilicus is either open, or nearly closed by a callus at the insertion of the columella. This species is distributed in the Mediterranean Sea, the Adriatic Sea, and in the Atlantic Ocean off the coast of Portugal.
