Sphaerolaimidae Filipjev, 1918

Leduc, Daniel, 2015, New species of Thelonema, Metasphaerolaimus, and Monhystrella (Nematoda, Monhysterida) from Kermadec Trench, Southwest Pacific, European Journal of Taxonomy 158, pp. 1-19 : 9

Family Sphaerolaimidae Filipjev, 1918

Diagnosis (from Fonseca & Bezerra 2014)

Cuticle striated or annulated. Six outer labial setae and four cephalic setae in one circle, with cephalic setae longer than outer labial setae. Eight groups of sub-cephalic setae present (four groups in Megalamphis ). Buccal cavity wide, barrel-shaped (except for Subsphaerolaimus Lorenzen, 1978 , which is conical), with longitudinal ribs, surrounded only at the base by pharyngeal tissue. Pharyngeal lumen with thick cuticle. Renette cell usually present, opening behind nerve ring. Females with one outstretched anterior ovary at left or right of intestine. Males usually with two testes; anterior one either to the left or right of intestine, posterior one at opposite side.