Subfamily Oxystomininae Chitwood, 1935
Diagnosis (modified from Smol et al. 2014)
Only dorsolateral orthometanemes, ventral gland when present confined within pharyngeal region. Amphideal fovea and aperture variable but amphideal aperture never elongated, precloacal supplements (when present) papilliform, in single ventral row. Females monodelphic-opisthodelphic.
Type genus
Oxystomina Filipjev, 1918
Other valid genera
Litinium Cobb, 1920
Nemanema Cobb, 1920
Thalassoalaimus de Man, 1893
Wieseria Gerlach, 1956