Family Selachinematidae Cobb, 1915

Diagnosis. (from Leduc (2013)). Body usually stout. Cuticle punctated with or without lateral differentiation. Head sensilla may be jointed. Amphideal fovea usually spiral, rarely loop-shaped. Buccal cavity spacious, divided into two compartments, either reinforced by cuticularised rhabdions in both portions (Choniolaiminae), or with posterior rhabdions modified into protrusible mandibles (Selachinematinae). Pharynx with or without posterior bulb, anterior bulb sometimes present. Males usually with two outstretched testes, either on same or different sides of the intestine; pre-cloacal supplements usually present, usually cup-shaped, sometimes setose, papilliform, rarely tubular. Female didelphic-amphidelphic with reflexed ovaries.