96 1^ ALLEN 



In Hexagrammos and Scbastodes the subclavians are essen- 

 tially the same as in Ophiodon, except that no vessel corre- 

 sponding to subclavian vein(3) was observed. In ScorpcBuich- 

 thys there were at least 3 internal subclavian veins (PL IV, fig. 

 30; Sub.V.(j-,); all of which broke up in the anterior fork of 

 the kidney. The external subclavian vein in Scorpcenichthys 

 (PI. IV, fig. 30; Sub.V.(^-)) instead of emptying into the sinus 

 venosus, breaks up in the anterior fork of the kidney, cephalad 

 of the internal subclavians. 



6. Hepatic Portal System. 



This system of veins returns most of the venous blood from 

 the stomach, spleen, casca and intestine. Some of the blood, 

 however, from the posterior part of the stomach and intestine, 

 reaches the right cardinal through the posterior mesenteric vein. 

 This vein anastomoses with the portal system in at least two 

 places. In Ophiodon there are 2 distinct portal veins, which 

 terminate in the right and left lobes of the liver. The right 

 portal returns the blood from the right side of the stomach, 

 spleen, and a portion of the intestine ; while the left portal 

 drains the ca;ca, ventral portion of the stomach, and a portion 

 of the intestine. In Ophiodon these 2 systems remain quite 

 well separated ; nevertheless, their branches anastomose in 

 several places in the region of the posterior end of the stomach, 

 but within the liver none of their branches unite. Each of the 

 portals breaks up into capillaries in its respective lobe, which 

 reunite in forming the right and left hepatic veins, and these 

 vessels unite in a sinus before emptying into the sinus venosus. 



(«) Right Portal Vein (PL I, figs, i and 2; R.Por.V.).— 

 In Ophiodon the right portal trunk is in itself a ver}' short ves- 

 sel, having its source from 2 principal trunks, one of them being 

 the right gastric vein, coming from the stomach, and the other 

 branch a vein formed by the union of the splenic and intestinal 

 vein^i). The right gastric vein (fig. i, R.Gas.V.) has its origin 

 in the posterior or cardiac portion of the stomach, where it 

 anastomoses with branch Z of the posterior mesenteric vein (fig. 

 I, P.Mes.V.) and the posterior gastric vein, which is a branch 

 of the left portal. The course of the right gastric vein is 



