240 ILLINOIS BIOLOGICAL MONOGRAPHS [450 



EXPLANATION OF PLATE 



Figures 218-239. Leidyana erratica (Crawley) Watson. 



Fig. 218. An adult sporont, X 245. 



Fig. 219. A younger slender sporont, nearly transparent, X 245. 



Fig. 220. Another adult sporont, X 245. 



Fig. 221. An old sporont, dense, compact and sluggish, just preparatory to cyst 



formation, X 245. 

 Figs. 222, 223. Drawings to illustrate bending of the body, X 245. 

 Fig. 224. The trophozoite attached to a host cell, X 245. 

 Fig. 225. A larger trophozoite with an incipient protomerite, X 245. 

 Fig. 226. Fully developed but still attached trophozoites, X 245. 

 Fig. 227. An individual with epimerite, free in intestine and nearly as large as 



the adults, X 245. 

 Fig. 228. A section of the caeca indicating that this organ is frequently the seat 



of infection. 

 Fig. 229. The sluggish sporonts attached by the sticky secretion from their bodies. 



They are not attached anterio-posteriorly by means of a socket as 



in the genus Gregarina but haphazard and barely contiguous. 

 Fig. 230. A cluster of sluggish fully matured sporonts, several of which formed 



cysts while on the slide under observation, X 60. 

 Fig. 231. An adult sporont from the original of Crawley and called by him 



Stenophora erratica. After Crawley, 1903, Plate III, Fig. 34. 

 Fig. 232. Longitudinal section of a portion of the deutomerite, indicating the 



deeply staining myonemes cut crosswise, just within the epicyte 



wall, X 500. 

 Fig. 2^2,- A sporont in the process of contortive and progressive movement. 

 Fig. 234. Two sporonts in the process of rotation previous to cyst-formation. 



The soporonts are not attached. X 120. 

 Fig. 235. A cyst still in rotation with a thin transparent wall, X 60. 

 Fig. 236. A cluster of sporonts after half an hour on a slide, endeavoring to 



free themselves from threads at the posterior end which hold them 



to the debris. The sporonts are greatly stretched owing to their 



efforts to move forward. 

 Fig. 237. A protomerite with an apical papilla. The animal is collapsing from 



evaporation of the medium. X 245. 

 Fig. 238. A cyst still in rotation, the nuclei faintly visible, the protomerites still 



distinct and the transparent layer thick. X 60. 

 Fig. 239. The nuclei have now disappeared and the protomerites are still visible 



as lighter areas. X 60. 



