A new species of the rare nematode genus Margollus Pena-Santiago, Peralta & Siddiqi, 1993 (Nematoda: Tylencholaimoidea) from Turkey.

Margollus turcicus sp. n., is described and illustrated from vineyard soil in Turkey. The new species is characterized by having a medium sized body (L=1.0-1.2 mm); cuticle with distinct striations; radial refractive elements abundant; lip region distinctly narrower than the adjoining body and slightly offset from the body contour by a depression; cephalic and labial papillae not discernible; strong labial and post-labial sclerotization present; amphids well developed with sclerotized walls; stylet 27-28.5 microm long, odontophore distinctly flanged, 0.3 times the odontostyle length; pharyngeal bulb offset by constriction, 33-37 microm long; mono-opisthodelphic female genital system with anterior branch 22-41 microm long; spicules 49 microm long; single weak ventromedian supplement and short hemispheroid tail in both sexes.