ANATOMICAL STRUCTURE OF KERRIA. 317 



Fig. 3. The genital zones seen from below and from the outside of the 

 bod J'. 

 2:>r. prostate pore. 

 $ . male pore. 



V. (jr. ventral groove between the two zones; the points of the 

 seta3 are seen protruding. 

 Fig. 4. A uephridium from somite xiii. 

 Fig. 5. The inner funnel of a nephridium. 



s. septum. 

 Fig. 6. Longitudinal section of the genital zone compiled from two 

 celloidin sections. 

 <j. 2. genital zone. 

 pr. prostates. 

 up. d. sperm ducts. 

 l>. s. genital or copulatory seta?. 

 Fig. 7. One of the epidermal appendages of the genital zone. 

 Fig. 8. Ovary and oviduct. 

 0. ovary. 

 od. oviduct. 

 Fig. 9. One of the genital sette of the inner couples in somites xvii, xviii 

 and xix. 

 One of the common settle. 

 Natural size. 



Kerr la zonalis, figs. 12, 13. 

 Common setaj. The genital sette are similar to fig. 9. 

 Testis and sperm-sac showing their connection, 

 testes. 

 .ss. sperm-sac. 



Plate XII. 



Kerria McDonaldi, figs. 14, 18, 21 to 27. 



Fig. 14. Schematic view of the spermathecaj and their position in front of 



the outer sette in somites ix and viii. 

 Fig. 15. One of the anterior spermathecfe, sectional view. 

 m. s. muscular part. 

 sc. spermathecal sac. 

 spz. spermatozoa. 

 Fig. 16. Another of the anterior spermathecse, outside view. 

 Fig. 17 and 18. Two of the posterior spermathecse, outside view, show- 

 ing the diverticula dvl. 

 Fig. 19. Part of the oesophagus, with diverticula, tubular intestine and 

 sacculated intestine, seen from above. Only the beginning of the 

 diverticula is visible. 



