Phylum Nemathelminthes :
(a) Commonly known as round worms or nematodes and covered by cuticle.
(b) Body is bilaterally symmetrical.
(c) Animals with elongated cylindrical and spindle-shaped body with pointed ends.
(d) The body cavity is a false coelom called pseudocoelom.
(e) The alimentary canal lacks a muscle layer.
(f) Respiratory organs and blood vascular systems are absent.
Example : Ascaris (Round worm), Oxyuris (Pin worm), Ancylostoma (Hook worm), Enterobius, and Rhabditis etc.