PHYLUM CHORDATA 



371 



Buccal cirri 



QUI slit inwall 

 of phorynx 



Afferent branch- 

 Jal arteries 



Ventral aorta 



Dorsal aorta 



. —Notochord 

 _ -Spinal cord 



■^ 



-Distribution throuqh 

 liver 



..HepaticV. 



. Subintestinal vein 

 . -Atriopore 



-Vcntro- intestinal V. 

 .Dorso-intestinai A. 



Anus 



Caudal vein 



1 Caudal artery 



Fig. 216. — Diagram of the circulatory system of Amphioxus. 



