Contributions to the Anatomy and Histology of Tbalassema neptuni Gaertner. 561 



The mesenteries consist af a dorsal mesentery attached to the 

 alimentary canal throughout its entire length, and a ventral mesentery 

 (supporting the blood vessel), which enters anteriorly and posteriorly 

 into connexion with the alimentary canal; anteriorly it forms a 

 diaphragm-like septum. 



A few irregular lateral mesenteric strands occur anteriorly and 

 posteriorly around the mouth and anus. 



