TWO AQUATIC OLIGOCH^TES. 



23 



sent in all the anterior segments except VIII. These vessels 

 enter into intimate relations with several internal organs, and 

 mnst therefore be described separately for each segment. 



The dorsal vessel is divided at its anterior end into two 

 branches, which are the commissures of segment I. They run 

 backwards on the dorsal side of the mouth cavity and after 

 undergoing a few windings in the first segment, open into the 

 anterior ends of the ventral vessels. 



In segment II, the commissures are given off from the dorsal 

 vessel at the posterior part of the segment. They proceed anteriorly 

 to the middle of the first segment, and then, turning backwards and 



ii 



in 



IV 



Fig. 13. 



L. gotoi. Dorsal view of the anterior 

 part of the body, showing the blood 

 vessels; reconstructed. xlOO. 



Fig. 14. 



L. gotoi. Dorsal view of segments 

 VII and VIII, showing the blood 

 vessels; reconstructed. xlOO. 



