176 ELECTRON-MICROSCOPIC STRUCTURE OF PROTOZOA 



Plate XX 



Fig. 74. Superficial section of Colpidium campylum, showing 

 one cilium, cut near its base, and two kinetosomes. M, primary 

 meridian between alveoli anterior to cilium; T, circular profiles of 

 transverse fibril band; P, circular profiles of postciliary fibrils; 

 K, segment of kinetodesmal fibril from next posterior kinetosome. 

 X 67,000. From Pitelka, 1961a. 



Fig. 75. Tangential section at surface of Paramecium aurelia, 

 intersecting polygonal ridges near their tops at right, more deeply 

 at left. Each pair of cilia occupies boat-shaped space outlined by two 

 outer pellicle membranes. A, cavities of pair of pellicular alveoli 

 surrounding a pair of cilia; M, longitudinal silverline meridian, 

 running horizontally in this picture; T, trichocyst tip embedded in 

 polygon ridge ; K, kinetodesmal fibril, x 22,000. From R. V. Dippell 

 and K. R. Porter, unpublished. 



