About Phorcus lineatus (da Costa, 1778)
The shell of Phorcus lineatus (da Costa, 1778) ranges in size from 10 mm to 35 mm. Adult shells are very thick, solid, and imperforate, while juvenile shells are subperforate. The shell has a globose-conic shape, and is dull grayish in overall color, covered entirely in dense, very numerous fine flexuous or zigzag braided purplish-black lines. The spire is conic, formed from 6 to 7 convex whorls. The apex is typically eroded and orange in color. The body whorl is flattened along its upper portion. The base of the shell is eroded in front of the aperture. The aperture is oblique. The columella is short, and is obtusely subdentate near its base; at its insertion, it spreads into a heavy callous that covers the umbilicus. This species shares a similar overall form with Phorcus turbinatus, but usually has more convex outlines along the spire. The columellar projection or tooth is positioned closer to the base than that of Phorcus turbinatus, and the distinct color patterns of Phorcus lineatus further separate the two species. Phorcus lineatus occurs in European waters within the ERMS scope, the Portuguese Exclusive Economic Zone, the Spanish Exclusive Economic Zone, the United Kingdom Exclusive Economic Zone, Wimereux, and in the Atlantic Ocean off the coast of Mauritania.
