of the Fishery Board for Scotland. 



13 



Fig. 5. Section of a ripe egg (in ovary). 



Fig. 5a. Envelopes of egg, . . . . . . x 



Fig. 6. Hair of endopodite, magnified. 

 Fig. 7. Part of long hair of exopodite, magnified. 

 Fig. 8. Part of short hair of exopodite, magnified. 

 Fig. 9. Ocular section of hair of exopodite, magnified. 

 Fig. 10. Transverse section of first penis at the base, magnified. 

 Fig. 11. Hair of exopodite, . . . . . . . x 



Fig. 12. Hair of exopodite, . . . . . . x 19 



Fig. 13. Abdomen, showing relation of the swimmerets. 



Fig. 14. Side view of the abdomen, showing the overlapping of the 



exopodites. 

 Fig. 15. Abdomen. 



Fig. 16. Transverse section of median part of first penis, magnified. 



Fig. 17. Ocular section of hair of exopodite, near its base. 



Fig. 18a. Longitudinal section of an egg which had been attached to a hair 



of the endopodite. January 11, 1901, . . x 57 



Fig. 186. Section of envelopes of 18a. 



Fig. 19. Shows the eggs retained in the " incubatory chamber," formed 



by the abdomen. 

 Fig. 20a. Third swimmeret, left side, posterior surface. 

 Fig. 206. Third swimmeret, left side, anterior surface. 



Fig. 21. Group of eggs attached to a hair. January 11, 1901, . x 5 



Fig. 22. Tip of hair of endopodite, magnified. 

 Fig. 23a & b. Tip of hair of endopodite, magnified. 

 Fig. 24. Tip of hair of endopodite, oc. 2, obj. 2 mm. O.I. 

 Fig. 25. Transverse section of the first penis, close to tip, magnified. 

 Fig. 26. Group of hairs of endopodite bearing eggs, magnified. 

 Fig. 27. Tip of hair of endopodite of Munida rugosa, magnified. 

 Fig. 28. Egg of Munida rugosa, attached to hairs of endopodite, . x 19 



Fig. 29. Attachment of egg-stalk to hairs of endopodite {Munida rugosa), 

 magnified. 



Fig. 30. Ocular section of the base of hair of endopodite, magnified. 



Fig. 31. Tip of hair of endopodite, magnified. 



Fig. 32. Ocular section of hair of endopodite, magnified. 



Fig. 33. Tip of hair of endopodite, magnified. 



Fig. 34. Section of dropsical ovarian egg with large perivitelline space. 



Fig. 35. Hair of exopodite, . . . . . . x 19 



Fig. 36. Hair of exopodite, . . . . . . x 19 



Plate III. 



The drawings, except where otherwise stated, belong to Cancer pagur us. 

 Figures 56, 57, 58, and 64 were outlined by means of the camera lucida. 



Fig. 37. First penis, posterior view. 



Fig. 38. Longitudinal section of mouth of the spermatheca of a hard 

 crab, 6 inches, showing three-layered wall of vagina and 

 spermatheca. 



Fig. 39. Fourth and fifth pereiopods, with genital papilla on coxopodite 

 of the latter : fifth pereiopod posterior in position. 



Fig. 41. Fourth and fifth pereiopods, with genital papilla: fifth 

 pereiopod anterior in position. 



Fig. 42. Outer surface of tip of exopodite of third swimmeret, left side, 

 magnified. 



Fig. 43. Sloughed-off outer skin of hair, with empty egg-capsules 



attached, magnified. 

 Fig. 44. Abdomen, with first and second penes in one position. 

 Fig. 45. Abdomen, with first and second penes in second position. 

 Fig. 46. Muscles of second penis, magnified. 

 Fig. 47. Genital papilla, magnified. 

 Fig. 48. Muscles of first penis, magnified. 



Fig. 49. Spermatheca of soft crab, 6| inches across. December 1st, 1899. pi. Plug 



Fig. 50. Tip of endopodite, inner surface, magnified. 



Fig. 51. Tip of exopodite, inner surface, magnified. 



Fig. 52. Muscles of abdomen, view from median line. 



Fig. 53. Second penis, anterior view. 



Fig. 54. Second penis, posterior view. 



Fig. 55. Diagram of relation of penis to the spermatheca and the plug. fl. Fluid 

 Fig. 55a. Coxopodite of fifth pereiopod, showing the perforation for the 

 issue of the vas deferens. 



