THE ANATOMY OF PENTASTOMUM TERETIUSCULUM. 73 



bulb is fused with it. Tlie muscular mass iu the rod-sac is attached by one 

 side to the outer wall, whilst the other has a strong chitinous lining. To one 

 side there is seen a trace of the opening into the cirrus-sac, which in this 

 specimen lies somewhat further back, than is represented in the diagram in 

 Fig. 62. 



Tig. 65. — Transverse section across the dilator rod-sac very slightly in 

 front of the section drawn in Fig. 64. The section passes through the lower 

 part of the muscular mass in the rod-sac where the chitinous layer is thick, 

 and through the root of the tongue-like structure (To.), and the cirrus bulb 

 just before the cirrus passes off from this. 



Fig. 66. — Transverse section across the dilator rod-sac very slightly in 

 front of the section drawn in Fig. 65. The tongue-like structure {To.) is cut 

 through, and the groove formed in the chitinous lining on the inner side, 

 through which the cirrus passes on its way to the cirrus-sac. 



Fig. 67. — Transverse section across the cirrus sliowing the two layers. 



Fig. 68. — Diagram to represent the common portion of the vesiculae semi- 

 nales and the method of union of this with the testis. A, B, C, D, E, F, G, 

 represent sections along the planes indicated by the lines bearing the same 

 letters in Fig. 68. 



