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. The stoma is divided into a cheilostome and an esophastome. In some species the male stoma is indistinct or collapsed. The cephalic sensilla are in the typical two whorl pattern: one circumoral and composed of six papilliform sensilla, while the second is a single whorl of ten setiform sensory organs which combines the ancestral two whorls of six and four. In some species the sensilla are all papilliform. The esophagus is generally conoid to cylindrical, and in some species in the posterior position is a series of muscular bulbs. The cuticle is generally smooth, and there are sensory setae or papillae scattered over the length of the body.