BLOOD-VASCULAR SYSTEM OF THE LORICATI 99 
corresponding arteries and unite in forming the left portal trunk 
directly in front of the point of bifurcation of the cceliac artery. 
Near its origin from the union of the two pyloric ceca veins 
the left portal, or occasionally it is the right pyloric cca vein, 
receives zutestinal vein. This vein (Pl. I, figs. 1, 6 and 11; 
Int.V.,,.)) usually has its source from the ventral side of the 
intestine close to the rectum. Its course is cephalad in the 
adipose tissue below the intestine. Before going very far, how- 
ever, it crosses to the upper side of the intestine, changing 
places with intestinal vein,,.. Then proceeding cephalad above 
the artery until the duodenum is reached, it crosses over the 
intestine, intestinal artery,,), intestinal vein,,,, the anterior part 
of the duodenum, the cceliac artery, and empties into the left 
portal close to its origin from the two pyloric ceca veins. Con- 
tinuing cephalad for a short distance between the stomach and 
liver and to the left of the coeliac artery, the left portal receives 
the anterior intestinal or duodenum vein (Pl. I, figs. 1 and 
11; A.Int.V.), which returns the blood from the anterior loop. 
The course of this vessel is at first directly behind the corre- 
sponding artery; then after passing under intestinal artery,,, and 
intestinal vein ,,, it ordinarily gives off or receives the connecting 
vein (figs. 1 and 6; C./V.’), a small vein which usually anas- 
tomoses with intestinal vein,,, a branch of the right portal. 
Then after passing over the anterior arm of the duodenum from 
which it receives a branch, it crosses the ceeliac artery, and after 
following along behind the hepatic artery for a short distance 
terminates in the left portal. The left portal enters the dorsal 
surface of the liver through 5 large radicals or terminal branches 
designated by the letters a to e (figs. 6 and 11). These vessels 
immediately penetrate the large left lobe of the liver and break 
up into the zzterlobular veins (fig. 11; I.Lob.V.), which, in 
turn, break up into venous capillaries. Usually several veins 
from the ventral surface of the stomach, designated as ventral 
gastric veins (fig. 6; V.Gas.V.), empty into some of these radi- 
cals, and some of the ventral gastric veins often penetrate the 
dorsal surface of the liver and break up into venous capillaries 
without emptying directly into the portal system. The posterzor 
gall-bladder vein (fig. 11; P.G.B1.V.), which arises on the 
