CILIATES 205 



course is unknown. Nothing resembling kinetodesma is apparent 

 in any micrographs of body ciliature. 



Primary emphasis in the paper of King et al. (1961) is on the 

 membranelles and underlying structures. Each membranelle 

 consists of four rows of 21 to 22 cilia, isolated from its neighbors 

 by a shelf of ectoplasm. Kinetosomes within each group are 

 directly linked by fibrils at their bases and about half-way distally ; 

 it was not determined whether these fibrils run along or across 

 the rows of basal bodies. From the base of each kinetosome arises 

 a group of fine fibrils that passes medially as a discrete bundle for 

 a distance of about 1 /x, then merges with a loose hexagonal 

 network of fibrils with dense nodes at the intersections. Root 

 fibrils from kinetosomes of a membranelle tend to converge and 

 show aligned nodes, so that a plate-like array of fibrils subtends 

 each membranelle and is identified as the basal plate of light 

 microscopists. The loose hexagonal mesh in which the basal 

 plates are embedded constitutes the ectoplasmic band. Its nodes 

 are about 100 m/x in diameter and the internode distance 225 to 

 450 m/x. On the opposite wall of the buccal cavity the meshwork 

 continues as the posterior ectoplasmic band, but here lacks basal 

 bodies. At certain locations structures identified as trichites occur. 

 These consist of regularly oriented tubular fibrils, about 20 m^t 

 in diameter. In some micrographs these appear to replace the 

 basal plates, in others they are clearly connected with the ecto- 

 plasmic band but their relationship with kinetosomes is not shown. 

 Some micrographs suggest the presence of bundles of fine 

 filaments forming a karyophore around the nucleus. In many 

 respects the ectoplasmic band structure of Njctotherus resembles 

 the reticulate infundibular fiber of the peritrich Campanella, 

 although the network appears more precise in the latter instance. 

 The converging root fibrils of each membranelle also roughly 

 resemble the membranellar fibrils of Stentor. 



Order Entodiniomorphida 



The Order Entodiniomorphida represents one of the peaks of 

 ciliate evolution. In these spirotrichs, all endocommensal in the 

 digestive tracts of herbivorous mammals, the ciliature is much 

 reduced. Some genera retain only an adoral zone of membranelles 

 that function both in feeding and in locomotion ; most forms have 



