BLOOD-VASCULAR SYSTEM OF THE LORICATI 105 
blood from the ileum; passing beneath intestinal vessels,,,) and 
the splenic vessels, it crosses under the anterior part of the 
spleen, where it joins a common trunk formed by the union of 
the right pyloric czca vein and a very large pylorus vern (fig. 
32, Pyl.V.). The common trunk thus formed is the left portal, 
but instead of breaking up into numerous radicals it empties 
with the left pyloric ceca vein (fig. 32, L.Cae.V.) and the 
ventral gastric vein (fig. 32, V.Gas.V.) into the common portal 
vein (fig. 32, C.P.V.). By anastomosing with the common 
portal, the right portal might also bé said to empty into the com- 
mon portal. 
Summary of the Portals. —As in the case with the corre- 
sponding arteries, intestinal veins,, .,a,) are arbitrary names given 
to the two principal intestinal veins. Considerable variation 
occurs in these two veins in the same species, but in Ophzodon 
the vessel designated as intestinal vein,,, arises in the posterior 
part of the intestine, and in its cephalic course along the ventral 
side of the intestine receives the splenic vein, and joining the 
right gastric vein forms the right portal. The corresponding 
vein in Ylexagrammos pursues a similar course ; while in Scope- 
nichthys the two intestinal veins unite and empty into the left 
portal; and in Sedastodes intestinal vein,,, drains only the pos- 
terior part of the intestine, and may unite with the splenic vein, 
or each of these vessels may empty separately into the right 
gastric vein to form the right portal. In every case the right 
portal breaks up in the right lobe of the liver. The vessel 
designated as intestinal vein,,) in Ophzodon arises from the 
ventral posterior end of the intestine and terminates in the left 
portal. In Hexagrammos this vessel might possibly correspond 
to an elongated duodenum artery; while in Scorpenzchthys if 
this vessel is represented at all, it unites with intestinal vein,,) 
and the combined trunk empties into the left portal; and in 
Sebastodes this is the principal intestinal trunk, arising from the 
iliac loop it unites with the right pyloric czeca vein to form the 
left portal trunk. All the genera but HYexagrammos have a 
posterior gastric vein; in Ophzodon it terminates in the right 
pyloric ceca vein; while in Scorpenrchthys and Sebastodes it 
empties into the splenic vein, a branch of the right portal. 
