I06 ALLEN 



Ophiodon and Scor^(2nichthys have a left gastric vein, which 

 empties into the precava ; while in Sehastodes and Hexagram- 

 mos the ventral gastric veins are greatl}' enlarged, and evi- 

 dently to some extent take the place of this vessel, nevertheless 

 in ScorpcBuic/ithys the ventral gastric is a good sized vessel and 

 anastomoses with the right gastric vein. In Ophtodon and 

 ScorpcBuichlhys there is a grand anastomosis in the cardiac 

 portion of the stomach of the branches of the right gastric, left 

 gastric, ventral gastric, posterior gastric and posterior mesen- 

 teric veins. Usually the right and left pyloric casca veins unite 

 to form the left portal, but in Sebastodes the right pyloric caeca 

 vein joins intestinal vein^^) to form the left portal, and the left 

 pyloric caeca vein empties into the common portal trunk. Ophi- 

 odon and Scorpcenichthys have a connecting vein in the region 

 of the spleen that links the 2 portal systems ; in Ophiodon it 

 usually connects intestinal vein^j^ with the anterior intestinal or 

 duodenum vein ; while in ScorpcBuichthys it connects the splenic 

 and common intestinal veins. Within the liver the 2 portals are 

 usually distinctly separated in Ophiodon and in Scorpcenichthys ; 

 while in Hex agr amnios radical a of the left portal anastomoses 

 with the right portal ; and in Sebastodes both portals together 

 with the ventral gastric and left pyloric caeca veins unite in 

 forming a common portal trunk, which gives off numerous 

 radicals that break up into the interlobular veins. 



7. Renal Poi-tal System. 

 Like the hepatic portal system the renal portal system con- 

 sists of two principal venous trunks, which are connected by a 

 system of venous capillaries within the kidney. One of these 

 trunks, the caudal vein, arises in the region of the tail and pur- 

 sues a cephalic course in the hasmal canal, immediately below 

 the caudal artery, receiving the neural veins from above and 

 the haemal veins from below. Piercing the dorsal surface of the 

 kidney it bifurcates into a right and left renal portal vein ; each 

 of these sends off numerous afferent renal veins that after 

 breaking up into capillaries reunite in numerous efferent renal 

 veins, which terminate in, and form, the right cardinal vein. 

 This trunk starts in the posterior end of the kidney, passing 



