542 JOSEPH STAFFORD, Anatomical structure "of Aspidogaster conchicola. 



Plate 38. 



Fig. 16. Genital system, as seen from above, partl}^ diagrammatic. 

 Uterus and yolk follicles left out. 16' Section of posterior end of bulbus 

 to represent the folding of the outer ductus. 



Fig. 17. Transverse section of penis apparatus, through the anterior 

 end of the papilla. W ^1^ = 246. 



Fig. 18. Same, through broadest part of bulbus , posterior to 

 section 17. Compare Fig. 9. W ^/^ = 480. 



Fig. 19. Part of a horizontal section between outer cuticle and 

 diaphragm, between C and D of Fig. 9, and in the plane PM of Fig. 2. 



Fig. 20. Four skin glands. The first opening through the cuticle 

 and with a drop of secretion at its mouth. 



Fig. 21. Part of a cross sciction , from the right side where the 

 diaphragm joins the body wall. 



Fig. 22. Infra-septal genital organs as drawn from a compressed, 

 young Aspidogaster. 



Plate 39. 



Fig. 23. Horizontal section through the posterior end. Compare 

 Fig. 8. 



Fig. 24. Three capillaries with their funnel organs and nuclei of 

 funnel cells. Two ciliary organs in a large vessel. First tri-radiate 

 division of the excretory system. 



Fig. 25. Portion of vitelline gland as seen in a living animal. 



Fig. 26. Portions of two dorso-venti'al parenchym muscles towards 

 posterior end of animal. 



Fig. 27. Testis from a sagittal section. 



Fig. 28. Transverse section of pharynx. 



Fig. 29. Some cells of the testis, taken from a horizontal section. 

 Two large ova-like cells. W ^j^ (Immersion). A spermatozoon pressed 

 out of a transsected living animal. 



Fig. 30. Portion of the posterior end of a vitelline gland, from 

 a longitudinal section. W ^ J .^. 



Fig. 31. a) Four subcuticular cells, b) A large gland cell seen 

 in a middle alveolus of the sucker, its neck pointing towards the margin. 

 From living animal. 



Fig. 32. Yolk-cells, from sections. 



Fig. 33. Outlines of cross sections through the posterior end, 

 1, 5, 10, 20 the number of the sections from the end. 



All transverse sections are viewed i'rom the postei'ior face, so that 

 all organs have their normal positions. 



