CLASSIFICATION OF ANIMALS 263 



Subclass B. Zoantharia 



Order 1. Edwardsiidea — Edwardsia 



Order 2. Actinaria — Metridium 



Order 3. Madreporaria — Astrangia 



Order 4. Zoantliidea — Zoanthus 



Order 5. Antipathidea — Antipathes 



Order 6. Cerianthidea — Cerianthus 



Phylum IV. Ctenophora (Sea Walnuts) 



Class I. Tentaculata 



Order 1. Cydippida — Fleurolrachia 

 Order 2. Lobata — Mnemiopsis 

 Order 3. Cestida — Cestus 



Class II. Nuda — Beroe 



Phylum V. Platyhelminthes (Flatworms) 



Class I. Turbellarla 



Order 1. Rhabdocoelida — Stenostomum 

 Order 2. Tricladida — Planaria 

 Order 3. Polycladida — Planocera 



Class II. Trematoda 



Order 1. Monogenea — Gyrodactylus 

 Order 2. Digenea — Fasciola 

 Order 3. As^idoaotylesi—Coty lapis 



Class in. Cestoda 



Order 1. Bothriocephaloidesi—Diphyllolothrium 

 Order 2. Tetraphyllidea — Crossohothrium 

 Order 3. Cyclopliyllidea — Taenia 

 Order 4. Trypanorhyncha — Ehyncolothrus 



Class IV. Nemertinea — Cerehratulus 



Phylum VI. Nemathelminthes (Roundworms) 



Class I. Nematoda 



Order 1. Ascaroidea — Ascaris 



Order 2. Strongyloidea — Necator 



Order 3. Filaroidea — Filaria 



Order 4. Dioctophymoidea — Dioctophyme 



Order 5. Tricliinelloidea — Trichinella 

 Class II. Gordiacea (Nematomorplia)— G^or^Zms 

 Class III. Acanthocephala — Echinorhynchus 



Phylum VII. Annelida (Segmented Worms) 



Class I. AvchiSinne\id2i.—Polygordius 

 Class II. Chaetopoda 



Order 1. Polychaeta — Nereis 



Order 2. Oligochaeta — Lumlricus 



Class III. Hirudinea — Hirudo 



Class IV. Gephyrea (Frequently classified as independent groups) 



Order 1. Echiuroidea — Echiurus 



Order 2. Sipunculoidea — Sipunculus 



