The roots also are affected, and instead of growing considerably in length, branch repeatedly and give rise to little tufts of rootlets.
The medusae, on the other hand, have the tentacles in four tufts of (in the buds) five each, and thus resemble the medusae of the family Margelidae.
Primitively there are four perradial tentacles, to which may be added four interradial, or they may become very numerous and are then scattered evenly round the margin, never arranged in tufts or clusters.
These hairs often occur in tufts, and are so colored and arranged that they were long taken for Fungi and placed in the genus Erineum.
The Priapuloidea are dioecious, and their male and female organs, which are one with the excretory organs, consist of a pair of branching tufts, each of which opens to the exterior on one side of the anus.