Clanculus clangulus (Wood, 1828)
Description: Whorls rounded, with spiral rows of closely spaced beads, sometimes with fine spiral ribs between the rows; very fine oblique lamellae between the spiral rows of beads. Base flat in juvenile specimens, rounded in adults; more finely beaded than sides. Basal margin sharply angled in juveniles, rounded in adults. In mature shells, outer lip thickened internally and ridged, with a tooth at the upper end. Columella with a large tooth almost centrally. Umbilicus open, margin toothed. Colour green with red splashes; spiral ribs of base regularly spotted with red.
Size: Up to 12 mm high, 12 mm wide.
Distribution: Restricted to NSW; Woody Head (Iluka) to Huskisson.
Habitat: Under rocks intertidally on the open coast; common.
Comparison: Clanculus brunneus is easily separated by its sharply angled basal margin and the obvious lamellae between the ribs. C. clangulus and C. floridus can usually be separated by colour; green with splashes if red in C. clangulus, reddish brown in C. floridus. An additional feature is that the rows of beads in C. floridus are constant in size and regularly spaced, whereas C. clangulus usually has rows of smaller beads between larger rows.
Figs. 1,2,3: Boat Harbour, Cronulla, NSW (C.349831)