1914] 



Sharp: Diplodinium ecaudatum 



85 



33) as well as all of the fibers described as leaving the motorium, 

 showed in all regions the same bright red color. Other fibers also 

 staining bright red are found in the oesophageal walls. These are 

 called oesophageal fibers (oes. f., fig. B; pi. 4, figs. 3, 4), but thus far 

 it has not been definitely decided whether they take their origin from 

 the motorium or directly from the circumoesophageal ring, probably 

 the latter, however. It was noted in the description of the oral cilia 

 that the root-fibers of these cilia end either in, or very close to, this 



D. 



d. m. 



o. d. lip - t 



d. m. sir. 



r. sk. a.- 



ador. m.*-~- 



dr. oes. r.< > j 



dr. oes. r. sir -> 



V. 



. a. 

 1 - - - ador. lip. sir. 



Fig. C. Diplodinium ecaudatum. Diagrammatic representation of the moto- 

 rium or neuromotor mass and its neuromotor strands seen from the anterior end. 

 X 1150. ador. lip sir., adoral lip strand; ador. m., adoral membranelles ; dr. oes., 

 circumoesophageal ring; dr. oes. r. sir., cireumoesophageal ring strand; D., dorsal 

 surface; d. lip str., dorsal lip strand; d. m., dorsal membranelles; d. m. sir., dorsal 

 motor strand; i. d. fur., inner dorsal furrow; i. d. lip, inner dorsal lip; 1. sk. a., 

 left skeletal area; m. m., motorium or neuromotor mass; o. d. fiir., outer dorsal 

 furrow; o. d. lip, outer dorsal lip; op. f., opercular fibers; or., oral opening or 

 cytostome; r. sic. a., right skeletal area; V., ventral side; v. m. str., ventral motor 

 strand. 



circumoesophageal ring. These root-fibers also show the bright red 

 color characteristic of w r hat is here called the neuromotor apparatus. 



In particularly well-stained whole mounts (stained with iron-alum 

 haematoxylin) the motorium, the dorsal motor strand, the ventral 

 motor strand, and the oesophageal ring show r very clearly Special 

 attention is here called to the microphotographs of this apparatus (pi. 

 6, figs. 14-16; pi. 7, figs. 21-26, 33). 



