Oncholaimida is an order of nematodes made up of a single superfamily, Oncholaimoidea. They are mainly marine and brackish water forms. They supposedly have predaceous and carnivorous feeding habits. Their amphids are pocket-like with oval apertures. The stoma is vase-like with walls that are heavily cuticularized. The stomatal armature contains one dorsal tooth and two subventral teeth, while the wall may additionally contain rows of small denticles.