Entoprocta

Entoprocta, a sub-class of Bryozoa (q.v.), including the four genera Loxosoma, Pedicellina, Ascopodaria, and Urnatella, and possibly also Barentsia. They are by far the simplest class of the Bryozoa, and even the adults are really in the stage of the larval form, known as the Trochosphere (q.v.). They have no body cavity, have one pair of nephridia or renal organs, and the sexes are united in the same individual. The main character of the class, however, is that the anus and mouth are both included within the circlet of arms. No fossil representative of the class is known.