Two remarkable new species of the genus Crassolabium Yeates, 1967 from Vietnam (Nematoda: Dorylaimida: Qudsianematidae).

Two new species of the genus Crassolabium are described from natural areas in Vietnam. Crassolabium aenigmaticum sp. nov. is characterized by its body 1.23-1.58 mm long, lip region continuous, odontostyle 17.0-19.0 μm long, neck 320.0-397.0 μm long, uterus tripartite, pars refringens vaginae with two triangular pieces separated by an intermediate sclerotized area, V = 54-59, vulva longitudinal, tail short and rounded in both sexes, spicules 43.0-48.0 μm long, and seven to eight spaced ventromedian supplements. C. vietnamense sp. nov. can be distinguished in having body 1.55-1.88 mm long, lip region offset by constriction, odontostyle 19.5-22.0 μm long, neck 370.0-448.0 μm long, uterus very long and tripartite, pars refringens vaginae with two close together pieces, V = 55-59, vulva transverse and usually covered with a plug, tail short and rounded in both sexes, spicules 53.0-55.0 μm long, and eight to nine spaced ventromedian supplements, two of them within the range of spicules. [ABSTRACT FROM AUTHOR]