172 



GEPHYTREA 



[OH. 



-'6 



FIG. 69. Dissection of Sipunculus 

 nudus. 



a. Frilled membrane surrounding 



the mouth. 



b. Ventral nerve-cord. 



c. Dorsal blood-vessel. 



d. Oesophagus. 



e. Cut ends of the intestinal coil. 

 /. Anus. 



g. Bush-bodies. 



h. Brown tube. 



i. Retractor muscle. 



;'. Blind pouch or caecum. 



