Natal to Madagascar and Mauritius, to Persian Gulf, to Red Sea, to eastern Mediterranean (Israel in 1971, Libya in 1994). Herbivore and grazer in the intertidal and shallow infralittoral, feeding on the encrusting algae that live on the surface of rocks. Synonyms: cruenta, jousseaumi, scutulum. – This specimen was said to come from Haifa, NW. Israel (4-8m deep, under rocks, 30mm) but the lack of recent confirmed finds make these data a little doubtful.

« Shell oblong, depressed, […] sculptured with coarse unequal spiral cords separated by deep interstitial grooves, usually more or less obviously radiately plicate in the vicinity of the spire, the penultimate and beginning of the last whorl usually having series of small pustules along the spiral cords; growth-striae very close and fine; perforations generally 6. […] The surface has numerous strong unequal spiral cords, more or less undulating and more or less tubercled, especially on the earlier part. There are usually low wave-like radiating folds on the inner part of the body- whorl, but these are often absent. There is great variation in the degree of elevation of the spire. Inside silvery, with red and green reflections, strongly spirally grooved. » – ibid. p.100.