a small grouping of abdominal worms getting the proboscis equipped with recurved spines
- phylum or course of elongated wormlike parasites that live-in the intestines of vertebrates: spiny-headed worms
- several intestinal worms, having the proboscis armed with recurved spines.
(n. pl.) A team of abdominal worms, getting the proboscis armed with recurved spines.
Certain additional small groups should probably be recognized as independent lines of descent or phyla, but their relationships are obscure - they are the Mesozoa, the Polyzoa, the Acanthocephala and the Gastrotricha.