BrcciNUM. 367 



Fig. 51a. Diagram showing how blood passes to renal 

 filaments by vessels crossing the lumen of 

 the renal organ. 



Fig. 52. T.S. Eenal filaments. x 200. 



Fig. 53. T.S. Secondary lamella, x 200. 



Fig. 54. Male gonad and ducts with penis. x 1. 



Fig. 55. Female gonoducts. x 1. 



Plate VIII. 



Fig. 56. Section of tubule of testis showing formation 



of spermatozoa. x 1. 

 Fig. 57a. Spermatid. 



Fig. 57b. " Hair-like " spermatozoon | 



-n- r-r <i TTT Ti >j X r after Retzius. 



rig. 57c. Worm-liKe spermatozoon j 



Fig. 58. Transverse section of ovary. Very slightly 



magnified. 

 Fig. 59. Transverse section of vaginal part of oviduct. 



Slightly magnified. 

 Fig. 60. Transverse section of ovary. x 150. 

 Fig. 61. Under surface of egg capsule showing pore of 



escape. x 1. 

 Fig. 62. Early stage in development of larva after 



cannibalism (after Koren and Daniellsen). 

 Fig. 63. Very early larval stage, otocysts present. 



(after K. and D). 

 Fig. 64. Late veliger larva (original). x 50. 

 Fig. 65. Egg capsules. Slightly reduced. 

 Fig. 66. Shells of young Buccinum at time of departure 



from egg capsules. x 10. 



