BLOOD-VASCUI.AR SYSTEM OF THE LORICATl II9 



the dorsal intestinal branch to form main intestinal vein ^^^^ 

 which shortly joins the rig/it gastric vein (tig. 37 ; R.Gas.V.) 

 to form the rig/it fortal. This trunk (fig. 37 ; R.Por.V.) 

 passes under intestinal artery^^^, and when the right lobe of the 

 liver is reached, sends off a branch to it, and anastomoses with 

 the left portal to form the common portal. The branch to the 

 right lobe of the liver receives the gall-bladder vein (fig. 37 ; 

 G.Bl.V.), which drains the entire bladder, and receives a 

 branch from a gland-like body marked G. 



The Icjt fortal vein (fig. 37 ; L.Por.V.) has its origin from 

 intestinal vein^,) and two pyloric cteca veins. Intestinal vein ^^.^ 

 (fig. 37 ; Int.V.(2)) arising from the iliac loop passes cephalad 

 below the corresponding artery, and after crossing under the 

 dorsal branch of intestinal vein^,), the spleen, and the ventral 

 branch of intestinal vein^) it receives a vessel coming from the 

 dorsal surface of pyloric caecum (3), designated as the right 

 pyloric aecavein (fig. 37 ; R.Cte.V.), and later the left pyloric 

 ccsca vein (fig. 37 ; L.C^e.V.), which arises from between the 

 fourth and fifth pyloric cseca. The left portal thus formed 

 curves around on the dorsal surface of the liver and anastomos- 

 ing with the right portal forms the common portal trnnk (fig. 

 38 ; C.Por.V.), which gives off several terminal branches or 

 radicals to the liver. Into this common portal is poured a rather 

 large ventral gastric vein (fig. 38; V.Gas.V.), which may to 

 some extent take the place of the absent left gastric vein found 

 in Ophiodon. 



The dorsal aorta presents no peculiarities, except that there 

 are a great number of spermatic arteries (fig. 37 ; Sper.A.), 

 usually 9 or 10. 



Renal Portal System. — In the kidney there is a complete 

 renal portal system. The caudal vein (fig. 37 ; Cau.V.) runs 

 along the left dorsal surface of the kidney as the renal portal 

 vein, giving off large afferent renal veins (fig. 37 ; A.Ren.V.) 

 to each side ; while the much smaller efferent renal veins (fig. 

 37 ; E.Ren.V.) return the blood to the right cardinal. This 

 trunk receives, directly, 9 or 10 spermatic veins (fig. 37 ; 

 Sper.V.) from the reproductive organs. The intercostal veins 

 (fig. 37 ; Intc.V.), however, do not empty directly into the 

 cardinal, but reach it through the efferent renal veins. 



