PLATE V. Structures and features of ciliates
revealable by use of transmission and scanning electron microscopy.

Fig. 1. Semi-diagrammatic representation of generalized cilium and associated kinetidal structures (modeled largely on Paramecium), with X-S's (a-e) at various levels as viewed from inside the organism looking out.

2. Bundle of microtubules (cross-linking not shown) comprising generalized nematodesma.

Various extrusomes

3. Clathrocyst (Didinium).

4. Rhabdocyst (Tracheloraphis).

5 a,b. Mucocyst, in place and discharging to exterior (Tetrahymena).

6 a,b. Haptocyst of suctorians, generalized form and in position at distal end of tentacle (Heliophrya, Acineta, etc.).

7. Patterns of microtubules (cross-linking not shown), as seen in X-S, in suctorial (a-f) and prehensile (g) tentacles of suctorians and rhynchodids (f) and in nonsuctorial tentacles of certain gymnostomes (h): a, Sphaerophrya; b,'Loricodendron (syn. Ophryodendron); c, Acineta; d, Dendrocometes; e, Cyathodinium; f, Ignotocoma; g, Ephelota; h, Actinobolina.

8. Illustration of fundamental differences between (a) pair of kinetosomes and (b) dyad, especially in orientation to body axis of organism.

9. X-S of generalized somatic kinetosome (modeled on Paramecium), near proximal (inner) end, as viewed from below (inside the organism) looking out, showing arrangement of microtubular triplets, numbering systems (Grain (outer) and Pitelka (inner numbers, in parentheses)] , and position of the "landmark" postciliary ribbon or band.

Various extrusomes

10. Extrusomes, discharged.
a. Toxicyst (Didinium).
b. Explosive trichocyst (Paramecium).
c. Fibrocyst (Pseudomicrothorax).

11. Extrusomes, undischarged.
a. Toxicyst (Didinium).
b. Explosive trichocyst (Paramecium).
c. Fibrocyst (Pseudomicrothorax).

12. Kinetosomal territories or kinetids (semi-diagrammatic and confined to somatic infraciliature) of diverse ciliates, showing kinetosomes in X-S (viewed from interior of cell looking out, with anterior end of organism's body toward top of page) and juxtaposition of some of the major associated fibers or microtubular ribbons [redrawn from various sources in the literature, with "i" from D. W. Coats, unpub.] :
a, Loxodes; b, Balantidium; c, Brooklynella; d, Ignotocoma; e, Trematosoma; f, Trichophrya; g, Espejoia;
h, Paramecium; i, Porpostoma; j, Conchophthirus;
k, Coelophrya; 1, Spirostomum; m, Sicuophora;
n, Plagiotoma.

13. Conspicuous postciliodesma in Stentor
(Huang & Pitelka).

14. Portion of rhabdos in Urotricha, showing circular arrangement of nematodesmata and lining of transverse microtubules
(de Puytorac & Grain).

15. Oral infraciliature of Tetrahymena
(Nilsson & Williams).

16. Oral area of Frontonia, showing particularly the nematodesmata

17. Area around left lip of cytostome in Paramecium (buccal cavity in foreground), showing formation of (new) food-vacuolar membrane (on left) by involvement of cytopharyngeal ribbons of microtubules, membrane-limited discs (upper righc and center), etc. ; part of quadrulus visible at lower right (Allen).

"Cut-away" ultrastructural views of pellicular and subpellicular (somatic) organelles and structures in selected ciliates. Note welldeveloped postciliodesmata in first two organisms, forms traditionally very distant taxonomically.

Fig. 18. Tracheloraphis, a "lower" gymnostome (Raikov et al.).

19. Blepharisma, a heterotrich (Gerassimova & Seravin).

20. Tetrahymena, a well-known tetrahymenine hymenostome (Allen).

More "cut-away" ultrastructural views of pellicular and subpellicular (somatic) organelles and structures in selected ciliates (see also figures of preceding page). Specializations shown in some detail in a well-known peniculine hymenostome and a complex pleurbnematine scuticociliate.

Fig. 21. Paramecium (Allen).

22. Conchophthirus (Antipa).