3261. Nemathelminthes. 23 Color Photomicrographs. 1. Ascaris lumbricoides, roundworm, t.s. of female 2. Ditto. t.s. of male 3. Ditto. ova 4. Enterobius vermicularis (Oxyuris), pin worm, female w.m. 5. Ditto., ovum 6. Trichuris trichiura, whip worm, w.m. 7