I04 ALLEN 



the pyloric branch of the left one extends backward on the car- 

 diac portion of the stomach as a sort of posterior gastric vein, and 

 anastomoses with branches of the posterior mesenteric vein ; 

 while the posterior gastric vein proper empties into the splenic 

 vein instead of the right cajca vein as in Ophiodon. Intestinal 

 vein^^s^ (fig- 29, Int.V.i-i^) arises from the posterior end of the 

 iliac loop ; the most dorsal of its branches anastomoses with 

 branch Z of the posterior mesenteric vein, and it receives a* 

 branch coming from the region of the rectum. In its cephalic 

 course, intestinal vein^j^ passes between the two arms of the 

 ileum, and receives a branch from the posterior part of the in- 

 testine designated as intestinal vein^^^ (fig. 29, Int.V.(2))> and the 

 anterior intestinal or dtiodemun vein (fig. 29, A.Int.V.). The 

 combined intestinal trunk thus formed passes under the anterior 

 arm of the duodenum and joins the left portal close to its origin 

 from the 2 pyloric caeca veins, but before emptying into the 

 left portal it receives or sends off a connecting vein (fig. 29, 

 C'.V.) that unites with the splenic vein. After reaching the 

 great left lobe of the liver the left portal immediately gives off 

 to each side numerous terminal branches or radicals, which 

 break up into the interlobular veins. As in Ophiodon, except 

 in a very few cases, radical a of left portal does not anastomose 

 with the right portal; it, however, receives the posterior gall- 

 bladder vein (fig. 30. P.G.Bl.V.), and also a very large ventral 

 gastric vein (fig. 30, V.Gas.V.), which anastomoses anteriorly 

 with the left gastric vein and posteriorl}?^ with a branch of the 

 posterior mesenteric vein. 



As in Ophiodon there is a left gastric vein (fig. 30, L.Gas.- 

 V.) emptying directly into the precava and two smaller left 

 gastric veins ; one of which empties into the precava and the 

 other into the left fork of the kidney ; while the main left gastric 

 vein anastomoses with branches of the ventral gastric vein, 

 which has branches that anastomose with branches of the pos- 

 terior mesenteric vein. 



The left portal in Sebastodcs (PI. IV, figs. 30 and 31 ; L.- 

 Por.V.) is a rather insignificant vessel, having its source from 

 a vessel designated as intestinal vein^o, and the right pyloric 

 creca vein. Intestinal vein^j) (fig. 31, Int.V.^,)) returns the 



