114 



Plate V. 



Fig. 35. General view of superficial blood vessels. 



Slightly enlarged. 

 Fig. 36. General view of arterial system. Slightly 



enlarged. 



Fig. 37. Venous System and especially circulation io 



Renal Organ. x 1. 

 Fig. 38. Veins on external surface of Oviduct, etc. 



x 1. 



Plate VI. 



Fig. 39. Transverse section of Ctenidial axis. x 40. 

 Fig. 40. Transverse section of Mucous gland. x 50. 

 Fig. 41. Nervous system. x 1. 



Fig. 42. Anterior Nerve centres, view from inside of 



nerve collar. x 6. 

 Fig. 43. Pedal Ganglia in male, x 6. 

 Fig. 44. Two leaflets of Osphradium. x 10. 

 Fig. 45. Transverse section of osphradial leaflets, 

 x TO. 



Fig. 46. Cells from osphradium (maceration prepara- 

 tion), x 400. 



Plate VII. 



Fig. 47. Transverse section through eye. x 140. 

 Fig. 48. Cells from retina (maceration preparation), 

 x 400. 



Fig. 49. Outer wall of renal organ with renal filaments 



seen from the lumen. x 1. 

 Fig. 50. Nephridial Gland seen from inner surface 



(facing lumen of renal organ). x 1. 

 Fig. 51. Outer wall of renal organ after removal of 



renal filaments, showing secondary lamellae. 



x 1. 



