Azygiida

Azygiida is an order of flatworms belonging to the class Rhabditophora.

Families:
 * Accacoeliidae Odhner, 1911
 * Aerobiotrematidae
 * Albulatrematidae
 * Aphanhysteridae
 * Aerobiotrematidae
 * Arnolidae
 * Azygiidae Lühe, 1909
 * Bathycotylidae Dollfus, 1932
 * Bivesiculidae Yamaguti, 1934
 * Botulidae
 * Bunocotylidae
 * Cylindrorchiidae
 * Dictysarcidae Skrjabin & Guschanskaja, 1955
 * Didymozoidae Monticelli, 1888
 * Halipegidae
 * Hemiuridae Looss, 1899
 * Hirudinellidae Dollfus, 1932
 * Isoparorchiidae Travassos, 1922
 * Lobatovitelliovariidae
 * Mabiaramidae
 * Oesophagicolidae
 * Pelorohelminthidae
 * Ptychogonimidae Dollfus, 1937
 * Sclerodistomatidae
 * Sclerodistomidae Odhner, 1927
 * Syncoeliidae Looss, 1899
 * Tetrasteridae