Abdominal tori position the body centrally in the lube, permitting lateral and dorsal body cilia to draw in water ventrally. pass it up between the parapodia, and expel it dorsally. Withdrawal involves contraction, peristalsis, and backward parapodial walking. Extensions of the paralhoracic palae effect forward locomotion, and parathoracic aeurosetae cause body twisting. In defecation abdominal neurosetae pass fecal strings anteriorly where a body retraction expels them ventrally from the tube.