"The velvet worms (Onychophora — literally “claw bearers”, also known as Protracheata) are a minor ecdysozoan phylum with ~180 species. These obscurely segmented organisms have tiny eyes, antennae, multiple pairs of legs and slime glands. They have variously been compared to worms with legs, caterpillars and slugs. Most common in tropical regions of the Southern Hemisphere, they prey on smaller animals such as insects, which they catch by squirting an adhesive mucus. In modern zoology, they are particularly renowned for their curious mating behaviour and for bearing live young.
The two extant families of velvet worms are Peripatidae and Peripatopsidae. They show a peculiar distribution, with the peripatids being predominantly equatorial and tropical, while the peripatopsids are all found in what used to be Gondwana.
Formerly considered part of Tracheata, velvet worms are now considered close relatives of the Arthropoda and Tardigrada, with which they form the taxon Panarthropoda. This makes them of palaeontological interest, as they can help to reconstruct the ancestral arthropod.”
[SOURCE: Onychophora - Wikipedia]