Therein an order Thoracica comprehends the pedunculate Lepadidae, together with the operculate and sessile Balanidae and Verrucidae; a single species without cirrhi constitutes the order Apoda, and a single species with only three pairs of cirrhi the order Abdominalia.
Hansen (Die Cirripedien der Plankton-Expedition, 1899) states that Cryptophialus minutus, for which the order Abdominalia was founded, has, like Alcippe and other Genuina, its cirrhi on the thorax, not, as Darwin wrongly supposed, on the abdomen.
In place, therefore, of the Abdominalia, it will be right to accept the family Cryptophialidae, v.