20mm. Thin or thick, dull, cap shaped, spire depressed, broader than tall, aperture flaring. Columella and callus pad smooth. Inner lip thickened and smooth inside; elongate tooth towards base of outer lip. Spiral ridges and fine growth lines. White, orange, beige or black variously patterned with blackish zigzags, spiral lines and dashes; columella, callus pad and aperture white or yellow-orange. Operculum finely granulated, glossy. Syn: N. anodonta Melvill, 1898. Habitat: intertidal on rocks.