Information about the pseudocoelomate group (also known as Aschelminthes or Nemathelminthes) of invertebrates, a group of about 10 separate phyla that are often clustered together. Most members of the group are soft-bodied worms, and many of them are microscopic. The most important phylum in the group is Phylum Nematoda, the roundworms. Other phyla in this group include Kinorhyncha, Rotifera, Acanthocephala and Nematomorpha.