Author: Jan Scholten
Genera: Phyla, Sipuncula, Hyolitha †, Nemertea, Phoronida, Bryozoa, Entoprocta, Brachiopoda, Mollusca, Annelida, Echiura.
Zoology: leeches as a sub-group of oligochaetes and oligochaetes as a sub-group of polychaetes. In addition, the Pogonophora, Echiura and Sipuncula, previously regarded as separate phyla, are now regarded as sub-groups of polychaetes. Annelids are considered members of the Lophotrochozoa, a "super-phylum" of protostomes that also includes molluscs, brachiopods, flatworms and nemerteans.
These are the worms in all kinds of forms. They have a bilateral symmetry and 3 germ layers, which is called triploblastic.
The traditional classification:
Polychaetes, almost all marine.
Oligochaetes, include earthworms.
Class Archiannelida (polyphyletic)
Class Echiura, previously a separate phylum)