lUi> 



Fig, 29. Section through tlie round typhlosole, canal- 

 like anterior end of pericardial cavity and posterior end oV 

 the body oi' the kidney. 



Fig. 30. Section tla rough the large, posteiloi* liver 

 mass. Shows the distribution and character ol" the two dif- 

 ferent parts. 



Fig. 31. Section through tlie large ventricle and the 

 ovai-y* 



Fig. 32. Section through the opening of the kidney into 

 the pericardial cavity, the anterior ganglion and ends of tho 

 auricles. The two arrows from the right indicate the course 

 of the v/ater currents between the gill laminae; the one 

 pointed dorsally, that of blood through the gill lamina. The 

 number and distribution of the inter-laminar connections in- 

 dicated by dots. 



Fig. 33. Section near the posterior end of the visceral 

 mass. 



Fig. 34. Section to illustrate the structui'C in the long 

 region botv/een the visceral mass and muscular collar. 



Fig. 35. Section thi-ough the "collar", palette handles 

 and base of the siphons. 



Fig. 3G, Section of a palette handle and its sheath. Tho 

 attachment of tlie ventral retractor muscle is shown, x b44. 



