BY VERA A. TRWI?^-SMITH. 



805 



moutli-cavity. They are probably digestive glands (Fig.53,c7.c//.). 

 The pliarynx is separated fi'om the remainder of the alimentary 

 canal by a sharp constriction. Behind tliis, the canal soon 

 widens out into a thin-walled tube (Fig. 51, r^.) formed of a single 

 layer of large cells, from fi^e to ten in cross-section, bounded 

 internally by a fairly thick wall, apparently composed of cuticle. 

 In side-view, the cells are pentagonal in shape, and ver}' large. 

 In the mid-region of the body, the alimentary canal becomes 

 narrower, and lies dorsal to the genital organs (Fig.55, int.). At 

 the level of the ^'entral setie, it again widens (Fig.52, inf.), and 

 its inner wall is thickened. Posteriorly, the intestine passes into 

 a wide rectum (Fig.56, re.) with thin walls of cuticle, wdiich opens 

 on the ventral surface by a narrow, transverse slit, the anal 

 aperture {a.). 



cut 



Fi^.Sj. M 



Fig. 53. — X tenax. 

 Sagittal, longitudinal section through antericjr end; ( x 830). 



A group of finely granular, somewhat pear-shaped bodies lies 

 above the posterior end of the pharynx (Fig. 53, yls.). From each 

 of these, one or more strands run forward towards the anterior 

 end. It is not possible, in any of the specimens examined, to 

 trace them to their termination; but it seems evident that they 

 end in the bases of the dorsal seta3, and that the l)odiesare glands 

 supplying the set?e with some sort of fluid.. 



