TWO AQUATIC OLIGOCILETES. 



39 



a---'— J& 



Fig. 29. 



L. willeyi. Pharyngeal glands. A, B — from seg- 

 ment IV and V. C — a whole gland in cross section, 

 from segment III. d — duct, n — nucleus, s— secre- 

 tions, nl — nucleolus, phr— endodermal cells of the 

 pharynx, ct— peritoneal connective tissue, bl — 

 vascular layer of the pharynx. 



is usually pear-shaped and 

 contains a large nucleolat- 

 ed nucleus ; the feebly 

 staining cytoplasm presents 

 an alveolar structure. The 

 cells are larger than in L. 

 gotoi, measuring 50-100 /•« 

 in length. 



4. Septa and Septal sacs. 



The complete septa 

 begin with the intersegment- 

 al line III/IV. Septa I/II 

 and II/Iir, which are absent 

 in L. gotoi, are incompletely 

 developed in this species, 

 being present only on the 

 ventral side of the alimen- 

 tary canal. 



The septal sacs lie on 

 the ventral side of the in- 

 testine and are attached to 



