516 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 
branches to the intestine on its way (Pl. VI, fig. 49, 
I. S. A., Int. A.). The abdominal aorta now curves 
ventrally, and can be seen on the ventral surface of the 
visceral mass, between the two diverging anterior ends of 
the kidneys (Pl. V, fig. 837, Add. A.). After giving off a 
fairly large branch to the septal muscle (fig. 42, Sept. A.), 
the abdominal aorta runs up alongside the intestine, to 
end in fine branches on the rectum. In its course it gives 
off several small intestinal branches, and also a second 
septal branch (fig. 42, Sept, A,). To the left of this is 
an important branch which terminates on the rectum, 
after giving off several ramifying branches to the surface 
of the liver, and a branch to the duct of the ink gland. 
The right branchial artery, soon after its origin, 
gives off a coronary artery to the walls of the 
ventricle. The left branchial artery, running 
behind the left kidney sac, soon bifurcates (Pl. VI, 
fig. 51, L. Bl. A.). One of the two forks running 
along to the oviduct, gives off one or two small branches 
to the auricle, and at the level of the oviducal gland 
sends off a recurrent branch which runs down between 
the water canal and the oviduct, to end in fine branches 
on the wall of the genital capsule (fig. 51, F,, Ree.). 
Other branches given off by this fork run to the flask- 
like portion of the coelom, to the anterior part of the 
oviduct (fig. 51, od.), and to the oviducal gland. The 
other fork (fig. 51, /’,), after giving off a branch to the 
genital capsule, runs over and feeds the branchial heart, 
sends a second branch to the gonad, and ends in a vessel 
running to the gill tip—alongside the branchial nerve 
—and supplying each leaflet with nutrient vessels (fig. 51, 
Bt. A.). 
The Genital aorta is an independent artery, given 
off by the postero-dorsal wall of the left chamber of the 
