Dikoleps nitens

Shell: Similar to S. serpuloides but with a taller, more pointed spire (apical angle 110–115°). Surface glossy, smooth, except occasionally a few spiral lines near the umbilicus. Umbilicus smaller, oval to comma-shaped, partly obscured by an out-turned inner lip. Outer lip with two sinuses: one at the periphery, another basally. Other features: Four swollen whorls. Aperture ear-shaped; peristome not planar. Umbilicus bordered abaperturally by a spiral ridge arising from the aperture base. Growth lines sinuous, matching outer-lip curvature. Colour white to brownish. Height and width up to 1.5 mm; last whorl comprises 90–95% of shell height, aperture 70%. Animal: Externally like S. serpuloides but lacking the right epipodial tentacle. White.

Recorded from Norway to the Mediterranean; in the British Isles, absent only from eastern Channel and North Sea coasts. Occurs among weeds and in pools on lower rocky shores (L.W.S.T.) and to 100 m depth.