Phylactolsemata, a division of the moss-like animals known as Bryozoa, It belongs to the subclass Ectoprocta (q.v.), which includes those that have the anus opening outside the ring of tentacles around the mouth. The characters that distinguish this division from its ally the Gymnolaomata are that the tentacles (or lophophore) are arranged in a horseshoe-shaped line and that the mouth is overhung by a small plate or epistome. The division is a very small one, and all the members are inhabitants of fresh water. There are in England 15 species belonging to five genera; Cristatella, Lophopus and Plumatella are the three best-known genera.