BLOOD-VESSELS OF MUSTELUS ANTARCTICUS. 
705 
discharge into the renal portal veins : the vein of the left side also receives the 
dorsal cutaneous vein {infra, p. 720). 
A. ii. System of the sub-intestinal vein : hepatic portal section. 
3. The hepatic portal vein. 
Pfortaderstamm, Stannius (25). 
Veine porte hepatique, Milne Edwards (14). 
Portal arterial vein, Owen (19). 
Vena porta, Huxley (10). 
The hepatic portal vein, or portal vein as it is more usually called (Plate 30, tigs. 
12 and 13, Hep. Port. V.), is a large vessel, fully 12 mm. in diameter when distended 
with injection, and lying in the gastro-hepatic omentum side by side with the anterior 
mesenteric artery. It is formed, at about the level of the pylorus, by the confluence 
of the intra-intestinal ( Intr. intest. V.), ventral intestinal ( Vent, intest.), and posterior 
lieno-gastric {Post. Ii. gast. V.) veins; somewhat caudad of the cardia it receives the 
gastro-intestinal {Gast. intest. V.) and ventral gastric ( Vent. gas. V.) veins; on 
reaching the liver it divides into two main branches, one for each lobe, besides 
sending off one or two lesser branches into the central portion of the gland. 
The intra-intestinal vein. 
Tronc veineux mesenterique (in Tlialassorhina and Zygcena), Duver- 
noy (6). 
Partie posterieure du tronc principal de la veine porte, ou veine 
mesenterique (in Zygcena, &c.), Milne Edwards (14). 
Main root of the portal vein (“in Plagiostomes with the longitudinal 
spiral valve”), Owen (19). 
Darmvene (“bei Petromyzon unci einigen Squaliden ”). Stannius (25). 
Intestinal vein (in Cyclostomes), Macalister (13). 
A special vein which lies in the fold of the spiral valve, Balfour (2). 
Intra-intestinal vein, Parker (22). 
This, one of the most interesting vascular trunks from a morphological point of 
view, was discovered fifty years ago by Duvernoy in Galeus (?) thalassinus 
(? Thalassorhinus) and Zygcena malleus, and was afterwards shown to exist also in 
Carcharias and Galeocerdo; all four genera of Selachians possessing a “scroll- 
valve ” (20) instead of the ordinary spiral valve. Duvernoy showed that the 
principal intestinal vein in these cases was a large vessel, with thick muscular 
walls, enclosed within the free border of the longitudinally rolled scroll-valve, and 
forming the chief factor of the portal vein. 
Special significance was given to this vein by Balfour’s discovery (1) that it is 
mdccclxxxvi. 4 x 
