Plectus parietinus Bastian, 1865.

Two females. Dimensions: L = 1.12-1.29 mm; a = 18- 22; b = 4.8 -5.3; c = 10-11; V = 11 -1345 - 471 0 "17.

This cosmopolitan species, easy to recognize, is apparently less common on Spitzbergen than several other species of this genus. Depth of stoma 28 \x. Amphids located just anterior to middle of stoma, their diameter 2.5 \x or one-eighth of corresponding body width. Excretory pore located at 56 % of neck length from head end. Hemizonid immediately anterior to excretory pore. Tail length equal to 3.1-3.4 anal body diameters.

Samples 4 and 63; juveniles in samples 1, 23 and 51.