CHAETOPODA, originally a zoological class, including all the Annelida (q.v.), except the Echiuroidea (q.v.). F. E. Beddard uses the term to cover the modern classes Archiannelida, Poly chaeta, Oligochaeta, Hirudinea (leeches) and Myzostomida (q.v.). Parker and Haswell (Textbook of Zoology) use the term to include only the Polychaetes and Oligochaetes. The charac teristic feature of Chaetopoda is the possession of bristles (setae). The term is now obsolete.