EUPLOTES WORCESTERI: I. 



295 



the individual meni1)ranellfe. The membranellaB of this series which 

 lie inside the pharynx may, for convenience, be termed the pliaryngeal 

 menibranella?. They vary in number; usually there are from twenty to 

 twenty-four, though a few more or less may l.ie found. It will be observed 

 that twenty-four memliranella?, are shown in text figure 5, and that this 

 section does not include quite 

 the full length of the pharynx. 

 Although the number of the mem- 

 branelhe inside of the pliarvnx 

 is sulijeet to considerable varia- 

 tion, I luive never noticed so small 

 a numlier as S. which is the 

 number Minkiewicz found in his 

 Black Sea specimens of E. vanuits. 

 I also find the pharrax to extend 

 considerably farther into the l)ody 

 than is represented l:>y the figures 

 of ilinkiewicz. It is often only 

 b>' very careful examination, even 

 with an immersion lens, that the 

 inner end of the pharynx can 

 accurately he outlined, partly 

 because of the thickness of overly- 

 ing granular protoplasm, and 

 jjartly because of the increased 

 delicacy of the vil)ratile organs in 

 the inner part of the phar3Tix and of the walls of the 2DliarjTix itself. 



The pharTOgeal membranella; lie on the rounded posterodorsal surface 

 of the pharynx, leaving part of the dorsal s\irface which is not occuiued 



Fig. 5. — A tangential section passing through 

 the dorsal wall of the pharynx. The rows 

 of basal granules of the pharyngeal mem- 

 branellfe and of the endoral cilia show the 

 arrangement of these organs. 



Fig. 6. — Part of a longitudinal section passing just inside the mouth, 

 s. 0., suboral membranella ; e. o,, endoral cilia, which in this section 

 are well down on the anterior wall. 



