ILLUSTRATIONS. 



Ventral view of Euplotes worcesieri sp. nov. Numerous refringeut endosare 

 spherules are visible, as well as three food-masses. 



Plate II. 



Fig. 2. View of Euplotes worcesteri from the left side. 



3. The dorsal surface of Euplotes loorcesieri showing the sensory bristles 



and radiating fatty granules. 



4. The ventral surface of Euplotes worcesteri showing the positions of the 



sensory bristles, the radiating fatty granules, and the contractile fibrils 

 running to the bases of the cirri. 



Plate III. 



Fig. 5. A longitudinal section of Euplotes worcesteri. Camera luoida draw- 

 ing; Zeiss compensation-ocular 6 and obj. J^. At the anterior end the 

 slight overhang of the dorsal surface and the marginal lamella are 

 shown. The section passes just mediad to the inner wall of the 

 persistome and mouth, cutting the pharynx, in which are seen the 

 pharyngeal and suboral membranellse. The meganucleus is cut in two 

 places. The smaller black bodies are nuclei of small flagellates eaten 

 by the Euplotes. The grouping of food-bodies is characteristic. 



6. A portion of the eotosarc in vertical section. Within the ectosarc alveoli 



is a portion of endosare, and a large food-body. The contents of the 

 ectosarc alveoli usually do not stain. Camera lucida drawing. 



7. A tangential section of the ectosarc. Camera luoida drawing. 



8. A section through one of the anal cirri, its basal plate, and its contractile 



fibril. The cilia of the cirrus are in the usual twisted condition. 

 Camera lucida drawing. 



9. A micronucleus, stained with iron-haematoxylin ; stain almost completely 



extracted, bringing into view the faint chromatin reticulum. 



TEXT FIGUKES. 



Fig. 1. Outline sketches of three of the deformed individuals which appear when 

 cultures have passed their prime. Specimen A seems to be the result 

 of an aborted division. 



2. A cross section passing through the mouth, the adoral membranellse, a. z., 



and the suboral membranellse, s. o. 



3. Cross section passing through the mouth, the suboral membranellse, the 



pharynx and pharyngeal membranellse, and the adoral zone. 



4. A longitudinal section, showing the antero-ventral groove of the pharynx. 



5. A tangential section passing through the dorsal wall of the pharynx. The 



rows of basal granules of the pharyngeal membranellfe and of the 

 endoral cilia show the arrangement of these organs. 



311 ■ 



