THE GENERA CERVIDELLUS THORNE, 1937 AND STEGELLETINA ANDRASSY, 1984 (NEMATODA, CEPHALOBIDAE) FROM IRAN, WITH DESCRIPTION OF STEGELLETINA-KHEIRII SP. N

One new and one known species of the genus Stegelletina and three spec ies of the genus Cervidellus were found in soil samples from Iran. Ste gelletina kheirii sp. n, is characterized by its convex-conoid tail wi th subacute terminus and by its anterior structure: labial probolae sl ender-conical with a single bifurcation, primary axils with single tri angular guarding piece appearing as two refractive U-shaped elements, lip margins in secondary axils with four pairs of rounded tines, witho ut refractive elements. S. kheirii sp. n is close to S. similis and S. devimucronata but differs from both mainly in the shape of the tail t erminus and absence of a U-shaped element in each secondary axil. Scan ning electron microscopic study of C. neftasiensis and C. vexilliger s howed that the extension of the lateral field on the tail and width of the phasmid opening are variable characters. S. devimucronata and C. cancellatus were also found and described here.