1. amphids not elaborate, oval, stirrup or pouch-like. 2. no body annuli. 3. cephalic sensory organs and somatic setae present or absent. 4. cylindrical esophagus, sometimes larger posteriorly. 5. five or more esophageal glands.
Orders: 1. Enoplida - marine and brackish water, feed on diatoms, algae etc.
2. Triplonchida - complex spear, esophagus gradually expanding from anterior to posterior.
Trichodoridae (plant parasites and vectors of plant viruses).