ON A PRORHYNCHID TUliBELLARIAN. 645 



Fig. 5. — Ventral view of the penis and its slieath reconstructed from 

 horizontal sections, c. m. Circular layer of muscle of penis sheath, ej. 

 Ejaculatory duct. l.m. Ijongitudiuai layer of penis sheath, p. Chitinous 

 tube of penis, p^. Investing layer of penis, pr. Protractor muscles, r. 

 Chitinous rods. x.x. Line of section of fig. 6. 



Fig. 6. — A transverse section of the penis and its sheath at about the line 

 marked x.x. in Fig. 5. Lettering as in Fig. 5. sh. Portion of ihe sheath 

 reflected on the penis at the anterior end. 



Fig. 7. — Section of vitello-ovary behind the vitelline region, fol. Follicle 

 cells, in. Investing fibrous layer, ov. Ovum. 



VOL. 40, PART 4. NEW SiSB. Y Y 



