Aulodrilus 603 



Fig. 5 and 6. — Spermathecae, X 195- 



Fig. 7. — Topographical position of the external spermathecal pore, X 94. 



Fig. 8. — Setae, X "64. 



Fig. 9. — Brain, X •'^88. 



Fig. 10. — Cross-section of segm. V, X 195. 



Fig. 11. — Cross-section of segm. VII, X 195. 



Aulodrilus pigueti sp. nov. 



Fig. 12. — Ventral view of sexual segments, X 94. 



Fig. 13. — Sagittal section through segm. VI — VIII in maturo spécimen, 

 X66. 



Fig, 14. — Cross-section of segm. VII of mature spécimen, X 66. 



Fig. 15. — Ventral view of segm. VII in another spécimen, as in Fig. 12., 

 X66. 



Fig. 16 and 17. — Maie reproductive organs, side- and ventral view, 

 X195. 



Fig. 18. — Setae, X 764. 



Plate 38. 



Fig. 19. — Latéral longitudinal section of segm. V and a part of segm. VI 

 in mature spécimen, X 195. 



Fig. 20. — Génital setae, their glands etc., in the last stage of develop- 

 ment, X 388. 



Fig. 21. — ïhe same, in an early stage of development, X 388. 



Fig. 22. — Génital seta, X 764. 



Fig. 2o. — Pénis, after a iiving spécimen. 



Fig. 24. — Topographical position of the external spermathecal pore, X 94. 



Fig. 25. — Spermatheca, side-view (a) and ventral view (6), X 195. 



Fig. 26. — Distal part of the spermatheca, normal (a) and protracted (b), 

 from a Iiving spécimen. 



Fig. 27. — Brain, X 388. 



Fig. 28. — A part of a cross-section of segm. VI, X 195. 



Fig. 29. — Cross-section of segm. VI, X 195. 



Fig. 30 — 32. — Three successive eross-sections of segm. Vil, X 195. 



Fig. 33. — Cross-section of segm. VIII, X 195. 



Fig. 34. — Ci'oss-section of the respiratory organ, X 195. 



Fig. 35 — 36. — Posterior end of the body with protracted and contracted 

 respiratory organ, X 94. 



Fig. 37. — Topographical position of the commissural vessels in the seg- 

 ments from the dissepimentum VI/VIII backwards, X 195. 



Fig. 38. — Beginning of the intestinal enlargement, in A. pi(/ueti (A.), A. 

 limnobius (B.), and A. 2Jluriseta [O, X 35. 



Fig. 39. — Four successive phases of a side-contraction of the respiratory 

 organ, as observed in Iiving spécimen. 



Fig. 40. — A phase of a side-con traction of the terminal i)art of tho respi- 

 ratory organ, as observed in Iiving spécimen. 



