Cantharidella picturata (Adams & Angas, 1864)
Description: Shell with rounded whorls, with four or five stepped, broad, flat ribs on each whorl. Basal margin rounded, base convex. Columella smooth, outer lip simple, not toothed. Umbilicus open, almost half covered by columellar callus. Coloration variable in pattern and colour; uniform black or red, but most commonly pale green background with red-brown axial streaks and red dots on the ribs. Interior iridescent.
Size: Up to 8 mm high, typically 5 mm.
Distribution: Endemic to Australia; Maroochydore, Qld, to Lakes Entrance, Vic.
Habitat: Under rocks on exposed coasts in the lower intertidal zone. Abundant.
Comparison: Similar in size and habitat to Eurytrochus strangei, but separated by its broad, flat ribs.
Synonym: Trochus albugo Watson, 1886 is based on a juvenile specimen of this species.Figs. 1,2,3: Port Jackson, Sydney, NSW (C.349143)