Rhabditida

Rhabditida is an order of free-living, zooparasitic and phytoparasitic microbivorous nematodes (roundworms) living in soil.

The Oxyuridae used to be included here, but they rather seem to belong in the Spiruria. Cephalobidae, Panagrolaimidae, Steinernematidae and Strongyloididae seem to be closer to the Tylenchia, regardless of whether these are merged with the Rhabditia or not.