- One Of Many two main categories of Chætopoda. It Offers those that have prominent parapodia and fascicles of setæ. See Illust. under parapodia.
- An order or other group of chætopodous annelids, getting the human body segmented, the untrue feet or parapodia with many ehætæ setæ or bristles (whence the name), and mind tentaculate; the polychætous worms.