Habit and differentiation of the actinotrocha. Increase in the number of tentacles; formation of the metasomal diverticula, the apical nervous thickening, the pear-shaped organ and of the adult tentacles. Metamorphosis to Phoronis: evagination of the mesodermal diverticulum; invagination of the gut into the diverticulum; formation of the ampule; transformation of the episphere and of the tentacle region; invagination of the telotrochs; circulatory system beginning to function. Habit and way of life of adult animal.