Benthimermithidae Petter, 1980 (taxonomy source)
Camacolaimidae Micoletzky, 1924 (taxonomy source)
Chromadorida (taxonomy source)
Chromadoridae Filipjev, 1917 (taxonomy source)
Cyatholaimidae Filipjev, 1918 (taxonomy source)
Desmodorida (taxonomy source)
Desmodoridae Filipjev, 1922 (taxonomy source)
Desmodoroidea Filipjev, 1922 (taxonomy source)
Desmoscolecida (taxonomy source)
Desmoscolecidae Shipley, 1896 (taxonomy source)
Desmoscolecoidea Shipley, 1896 (taxonomy source)
Enchelidiidae Filipjev, 1918 (taxonomy source)
Enoplea (taxonomy source)
Enoplia (taxonomy source)
Enoplida (taxonomy source)
Enoplina (taxonomy source)
Enoploidea Dujardin, 1845 (taxonomy source)
Ironina (taxonomy source)
Ironoidea de Man, 1876 (taxonomy source)
Leptolaimidae Örley, 1880 (taxonomy source)
Meyliidae De Coninck, 1965 (taxonomy source)
Microlaimidae Micoletzky, 1922 (taxonomy source)
Microlaimoidea Micoletzky, 1922 (taxonomy source)
Monhysterida (taxonomy source)
Monhysteridae de Man, 1876 (taxonomy source)
Monhysterina (taxonomy source)
Monhysteroidea Filipjev, 1929 (taxonomy source)
Oncholaimina (taxonomy source)
Oncholaimoidea Filipjev, 1916 (taxonomy source)
Oxystominidae Chitwood, 1935 (taxonomy source)
Phanodermatidae Filipjev, 1927 (taxonomy source)
Plectida (taxonomy source)
Plectina (taxonomy source)
Sphaerolaimoidea Filipjev, 1918 (taxonomy source)
Xyalidae Chitwood, 1951 (taxonomy source)

 Biology

 for Tripylium Cobb, 1920

Commensal or ectoparasitic on gills of land crabs. [details]

 Biology

 for Tripylium calkinsi Chitwood, 1935

Commensal or ectoparasitic on gills of land crabs. [details]

 Biology

 for Tripylium carcinicola (Baylis, 1915) Cobb, 1920

Commensal or ectoparasitic on gills of land crabs. [details]

 Biology

 for Tripylium carcinicolum Baylis, 1915

Commensal or ectoparasitic on gills of land crabs. [details]