PLATE VII. Position of the oral area vis-à-vis the apical pole of the body in several groups of ciliates.
Fig. 1. Mouth or cytostome terminal, directly at apical pole
(Holophrya).
2. Mouth shifted eccentrically (Enchelys).
3. Mouth on ventral surface, to different extents (Spathidium)
4. Mouth on ventral surface, to different extents (Glaucoma).
5. Apically located (Prorodon).
6. Plagiopyla
7. Dileptus
8. Colpidium
9. another Colpidium
10. Paramecium.