Cryptoplax depressus Blainville, 1818Chiton leachi Blainville, 1825Chiton monticularis Quoy and Gaimard, 1835Cryptoconchus stewartianus Rochebrune, 1882Acanthochites porosus Suter, 1913 Cryptoconchus porosus, the butterfly chiton, is a species of chiton, a marine polyplacophoran mollusc in the family Acanthochitonidae.

[1][2][3] Cryptoconchus porosus is a large chiton reaching a length of about 45–75 millimetres (1.8–3.0 in).

[4][5] The eight valves are almost completely covered by a raised girdle, young specimens may have only seven.

The girdle is fleshy and smooth with short sutural bristles that protrude from 18 rounded pores, which are elevated and run in two crested rows from head to tail.

[8] These common grazers prefer outer exposed rocks washed by waves, in the low intertidal and shallow subtidal zone, or in deeper water down to 30m, often in association with sponges.