Broadly oval, plates strongly keeled. Each plate divided into a broad triangle toward the front, and 2 wedge-shaped triangles at the sides. Main triangle marked with longitudinal grooves, side triangles bear transverse wavy ridges. Front and back plates pimpled with small tubercles. Colour olive-green, clouded and speckled with greenish. Conspicious girdle heavily scaled; pale green, with squareish patches of black or dark green, suggesting a border of snake skin.
This large Chiton (5-7.5 cm long) occurs in great numbers
on rocky intertidal areas of both north and south shores.