(a) : Acoelomates are animals having no body cavity or coelom. Examples are poriferans coelenterates, ctenophora, platyhelminthes and nemertinea. In pseudocoelomates, body space is pseudocoelom or false coelom. Examples are ectoprocta, aschelminthes. In coelomates, body space is a true coelom enclosed by mesoderm on both sides. Remaining phyla of bilateria, from annelida to arthropoda are coelomates. Molluses and insects are coelomates while flatworms are acoelomates.