386 



MR. R. H. BURNE ON THE VEINS OF A SEAL. 



[Mar. 1. 



Particular attention was drawn to a pair of venous plexuses * 

 (V.Pl.) connected with the ventral surface of the vena cava just 

 above the sphincter venae cavse. The plexus consisted of a coil of 

 branching veins of considerable size and a relatively minute artery 

 derived from the phrenic artery (Ph.A .). The blood-vessels with a 

 small amount of fat lay enclosed within a sac of pleural membrane 



Text-fig. 39. 



The thoracic and hepatic vena cava inferior and liver of a Seal (Phoca mtulina). 



D. Diaphragm ; _ZJ. Liver ; Ph.A. Phrenic artery ; Ph.N. Phrenic nerve ; 

 Pl.M. Pleural membrane (cut edge); Spk.V.C. Sphincter venae cavae ; 

 V.C.I. Vena cava inferior (thoracic); V.Pl. Venous plexus ; VS. Venous 



(Pl.M.), the whole structure projecting freely into the pleural 

 cavity at the point of contact of the pleura and pericardium. 

 The margins of the pleural sac were produced to form a fringe of 

 arborescences, which were compared (following a suggestion of 

 Professor Keith) with the fimbriae of the synovial fringes in the 



* The plexus of the left side was accidentally removed. 



