CHILOPLECTUS-MASLENI SP-NOV AND VARIABILITY IN POPULATIONS OF PLECTUS-ACUMINATUS BASTIAN 1865 (NEMATODA, PLECTIDAE) FROM THE NUNATAK BASEN,VESTFJELLA, DRONNING MAUD LAND, EAST ANTARCTICA

A new species, Chiloplectus masleni sp. nov., and 12 populations of Pl ectus acuminatus are described from the nunatak Basen, Vestfjella, Dro nning Maud Land, East Antarctica. C., masleni sp. nov. is distinguishe d from the closely related C. loricatus by a broader lip region, longe r stoma, the more posterior position of amphids, a pear-shaped basal b ulb, more narrow annuli, anterior annuli that are evenly rounded and a larger number of tail setae. New information is provided on internal and external morphology of specimens of P. acuminatus from Basen.