102 ALLEN 



it anastomoses with branch Z of the posterior mesenteric, and 

 the posterior gastric veins. The sflenic vein (fig. 29, Spl. V.) 

 leaves the anterior surface of the spleen, which is located 

 directly above the pylorus, and passes forward to unite with 

 the right gastric vein in forming the right portal, but immediately 

 after leaving the spleen it receives the poste7-ior gastric vein 

 (fig. 29, P. Gas. v.), which in Ophiodon emptied into the right 

 cgeca vein, a branch of the left portal. The right portal, itself, 

 is almost identical with the same vessel in Ophiodon ; it receives 

 a small vein from a gland-like body marked G, and shortly 

 before entering the right lobe of the liver receives the anterior 

 gall-bladder vein which does not anastomose with the posterior 

 gall-bladder vein as in Ophiodon. Usually the right portal 

 breaks up in the small right lobe of the liver without anasto- 

 mosing with terminal branch a of the left portal. 



Beside the ordinary branches which go to make up the right 

 portal in Ophiodon, there is an additional one in Sebastodcs, 

 namely, the anterior air-bladder or air-bladder retia mirabilia 

 vein (PI. IV, fig. 31 ; A.Bl.V.). This vessel arises from the 

 retia mirabilia venous capillaries, which are continuous with, 

 and run parallel to, the corresponding arterial retia mirabilia 

 capillaries. These venous capillaries unite in forming larger 

 vessels that terminate in the main anterior air-bladder vein, 

 which pierces the ventral wall of the bladder and empties into 

 the right gastric vein. The latter vessel, as in Hexagrammos, 

 has its origin in the posterior end of the stomach without hav- 

 ing any posterior mesenteric vein with which to anastomose. 

 Shortly after receiving the anterior air-bladder vein the right 

 gastric receives the vessel designated as intestinal vein(i). This 

 vessel (fig. 31, Int. V.(i)) arises in the rectum and drains the 

 posterior portion of the intestine. In its cephalic course, par- 

 allel with the corresponding artery, it follows along the poste- 

 rior border of the spleen ; in Sebastodcs favidtis (fig. 33) it was 

 seen to unite with the splenic vein as in Ophiodon, while in 

 Sebastodcs auriculatus both vessels emptied separately into the 

 right gastric vein. . Shortly before joining the right gastric, or 

 splenic vein as it is in ►S'. JJavidus, intestinal vein^,) usually re- 

 ceives a posterior gall-bladder vein (figs. 31 and 33, P.G.Bl.V.) 



