101 



Plate V. 



Transverse section of oesophagus (enlarged). 

 Transverse section of tubules of posterior 



salivary gland. 

 Transverse section of tubules of anterior 



salivary gland. 

 Transverse section of secretory tubule of 



salivary gland, showing secretory cells. 



Kidneys, seen from ventral surface, after 

 removal of visceral envelope. Female. x 1. 



Spiral caecum, opened along coluniellar edge 

 of spiral, and walls pinned back. The series 

 of transverse valves may be seen, and the 

 internal aperture of the hepato-pancreatic 

 duct. x 1. 



Fig. 38«. View of viscera, after removing kidney and 

 heart, and turning liver forward — from 

 ventral surface. x \. 



Fig. 39. Ovary, and female genital ducts. The ventral 



germinal wall has been turned forward 



anteriorly. x 1. 

 Fig. 40. Sketch showing relation of pericardial division 



of coelom to water vascular canal and ureter. 



Reno-pericardial aperture seen at base of 



opened ureter. x |. 



Fig. 41. View of portion of germinal wall of ovary, from 

 inner surface, showing attachment of the eggs 

 in racemes. x -i. 



Fig. 59. Right gill — ventral view. x 1. 



Fig. 60. Portion of gill, from inner surface, showing 

 alternating arrangement of inner and outer 

 leaflets: the central inner leaflet removed. 

 (Enlarged.) 



Plate VI. 



Fig. 42. Injection of arterial system, showing the dis- 

 tribution of the main brachial, cephalic, 

 pallial, genital and visceral branches. From 

 ventral surface partly diagrammatic. x f. 



