380 MOORE. 



e, external, and i, internal, compartments. 



Other lettering as in Fig. 43. 



Fig. 50. B. illuminatus. Transverse section through the anterior chamber of 

 the vesicle. X 500. 



Lettering as in Fig. 45. 



Fig. 51. B. illuminatus. Longitudinal section of the anterior nephridial 

 vesicle. X 500. From Journal of Morphology, vol. x, no. 2. 



c, internal compartment. 



OT, muscular layer. 



Fig. 52. B. philadelphicus. A section through the nucleated portion of 

 peritoneal cell ; from the nephridium. X 880. 



Fig. 53. B. illuminatus. A few clusters of granules from the enlarged peri- 

 toneal cells of the nephridium. X 900. 



Fig. 54. B. illuminatus. A small portion of the apex of the long tubule loop, 

 showing the bacilli-like markings of the inner surface, represented partly as an 

 optical section, partly as a surface view. X 900. 



