384 MR. WALTER WESCHE ON THE GENITALIA OF 



Fi;;. 15. Central organ of Gynoplistia bella, Westw., sho^^ing the three apodemes and the changes in the 

 theca. 



16. Forceps superior of Cule.v (?). This part in C. pipiens only differs by the articulated bristle at 



the extremity of the hook being of a different shape. 



17. Ventral view of Iiypopygium oiPtychoptera scutellaris, showing the situation of the ejaculatory 



apodeme ; the penis has been removed, and is shown in fig. 20. 



18. Ejaculatory apodeme of P. scutellaris. 



19. Forceps superior of Gynoplistia bella. 



Plate 24. 



Fig. 20. Central organ (penis) in P. scutellaris. 



21. Ovipositor of Tipula oleracea, Linn., lateral view. 



22. Forceps superior of T. oleracea. 



23. Theca and flagellum of T. oleracea. 



24. Diagram of the last segments of the male abdomen, of T. oleracea, to show the arrangement of 



the ejaculatory apparatus. The forcipes superiores and inferiores have been removed. 



25. Forceps inferior of T. oleracea. 



26. Ejaculatory sac and apodeme of T. oleracea. 



27. One of the processes which constitute the sense-organ on the plate of the forceps inferior of 



T. oleracea, seen from above. 



28. The same part in section. 



29. Theca and flagellum of Pacliyrrhina maculosa, Meig. 



30. Ejaculatory sac and apodeme of P. maculosa. 



31. The same apodeme enlarged. 



32. Extremity of the ductus ejaculatorius and forcipes interiores oi Berts vallata (Forst.). 



33. The last segments of the abdomen of the male of B. vallata, drawn diagrammatically to show 



the arrangement of the parts. 



34. End of abdomen of B. vallata ? . 



35. End of abdomen of B. nigra, Meig., ? . 



36. Forceps inferior of an undetermined Asilid from Mt. Gambler, S. Australia. 



37. Forceps superior of same insect. 



38. Ejaculatory duct of same insect, showing the arrangement of the ejaculatory sac and apodeme 



in the base of the theca. 



Plate 25. 



Fig. 39. Penis of Empis stercorea, Linn. 



40. Forceps superior of E. stercorea. 



41. Penis of Hilara cilipes, Meig. 



42. Ovipositor of H. cilipes. 



43. Hypopygium of Dolichopus plumipes (Scop.). 



44. Orifice of the ejaculatory duct and the end of the theca of D.festivus, Hal. 



45. Spinus titillatoriiis of D. festivus, Hal. 



46. Forceps interior of D. festivus. 



47. Palpus genitalium of D. festivus. 



48. Palpus genitalium? of D. festivus (doubled part). 



49. J^nA of i^enis of Poscilobothncs nobilitaius (Linn.). 



50. Penis, ejaculatory apodeme, and vas deferens of Dolichopus griseipennis, Stann. 



51. Part of same, enlarged and drawn diagrammatically to show the working of the ejaculatory 



apparatus. 



