This shellfish is typical of a separate class of molluscs which stands uniformly distinct from all other groups. The shell is always composed of eight movable pieces fastened together by muscles and a surrounding leathery girdle, which is often studded with scales. Variation in the number of valves of the shell is not unknown, but such can always be traced to some injury. Chitons are vegetarian feeders, but spend most of their time fastened to rock by suction. About 60 New Zealand species are known, but many of them are very rare. One species, Cryptoconchus porosus, has beautiful greenish-blue internal valves. These are the “butterflies” so keenly sought by amateur collectors. Many chitons have interesting composite eyes which are actually studded as tiny pinpoints on the outer surface of the shelly valves. Our largest chiton grows to 4½ in. in length.
by Arthur William Baden Powell, Assistant Director, Auckland Institute and Museum.