32 Cincinnati Society of Natural History. 
The somatic veins have already been described in a general 
way. Those of the abdominal region pass dorsal to the cor- 
responding mesonephros (receiving no branches from them), 
and empty into the corresponding posterior cardinal vein. 
The posterior cardinals receive no veins from the intestine. 
In one instance only I observed a branch from the testis 
runuing upward into the right posterior cardinal vein. 
Anteriorly, a short distance behind the heart, the right 
and left posterior cardinals unite again to form the unpaired 
posterior common cardinal vein (Fig. XVII, pec), which passes 
forward on the left side, and empties into the posterior end 
of the sinus venosus. 
The sub-intestinal vein (Figs. XI, XV, XVII, XVIII, sub. 
int.) arises from the ventral wall of the intestine toward the 
anterior end. It passes forward along the median ventral 
line of the intestinal wall, and on reaching the hepatic liga- 
ment, passes down along its posterior margin to the posterior 
lobe of the liver. (Fig. XI.) In some specimens it passes 
through the tissue of the liver for a considerable distance, 
but in others it runs along the surface, within the serous 
membrane. It passes behind the liver, and runs forward on 
its ventral and external aspect. It receives branches from 
the posterior lobe of the liver, and becomes the posterior 
hepatic vein (hp). As such it passes upward, parallel and 
near to the bile duct of the posterior lobe. It becomes very 
much widened, and finally empties into the posterior end of 
the sinus venosus, opposite the common posterior cardinal 
vein. 
The veins of the anterior lobe of the liver converge to form 
the anterior hepatic vein, which lies on the dorsal surface of 
the lobe. (Figs. XI, XVII, XVIII, ha.) This vein runs 
forward and upward, emptying into the left side of the sinus 
venosus, a little behind-the sinu-auricular opening. 
There is also apparently a small vein running in the liga- 
ment between the anterior end of the posterior lobe, and the 
posterior end of the anterior lobe. The veins from the gall 
cyst, as will be seen, join the portal system, and will be de- 
scribed there. 
20 
