Flatworms constitute the phylum Nematoda.
False
Anatomically, Nematodes and Platyhelminthes are almost similar. The nematodes or roundworms constitute the phylum Nematoda. The flatworms, flat worms, Platyhelminthes, Plathelminthes, or platyhelminths are a phylum of relatively simple bilaterian, unsegmented, soft-bodied invertebrates.