Acrobeloides tricornis (Thorne, 1925) Thorne, 1937

(Fig. 1, A-C).

Five females. Dimensions: L = 0.36- 0.48 mm; a = 15 -18; b = 2.7 -3.6; c = 19-23; V = 9 _1 665 -661 0 -1 8. The specimens agree well with Thome's original description. The swelling of the corpus is distinct. The nerve ring surrounds the isthmus; opposite it is the excretory pore and a distinct hemizonid two annules long, immediately behind the excretory pore. Cuticular annulation 2 [x wide,shallow and indistinct over the greater part of the body. Tail with nine to ten annules. Vulva lips slightly protruding. The postvulvar part of the gonad extends farther from the vulva than the prevulvar part. Rudiment of second gonad shorter than body width. The double flexure behind the vulva is well developed in one specimen only. Dimensions of an intra-uterine egg: 52 x 19;x. The intestine is densely filled with globules so that the gonad does not show up very well.

Samples 17, 18, 21, 42, 54, 65, 66 and 67.