BLOOD-VASCULAR SYSTEM OF THE LORICATI 69 
supply for the viscera of Scorpenichthys is most like Ophiodon, 
and Sebastodes most like the ordinary Acanthopterygian fishes. 
The origin of the cceliaco-mesenteric trunk is the same for all 
4 genera studied, but as regards the branching of the cceliac 
and especially the mesenteric, there is considerable variation. 
Celiac Artery. —In Hexagrammos the ceeliac branches off 
from the cceliaco-mesenteric trunk much further caudad than is 
the case with the other 3 genera; in fact, the cceliac and the 
left gastric are given off together. In all 4 genera the cceliac 
terminates by dividing into the 2 pyloric ceca arteries, but in 
Ophiodon only does a pyloric ceca artery supply the posterior 
part of the stomach. In Sedastodes the left hepatic arteries 
(Pl. IV, fig. 32: L.Hep.A.) arise in a similar manner to 
the corresponding vessels of Ophzodon, except that the pos- 
terior left hepatic artery is much larger than in Ophzodon ; while 
in Scorpentchthys and Hexagrammos, strange to say, the left 
hepatic arises from the right gastric, but in Hexagrammos it 
comes into such close contact with the cceliac that at first one 
might be led to believe it arose from the cceliac or at least anas- 
tomosed with it. In Hexagrammos only does the intestinal 
artery.) arise from the ceeliac as in Ophzodon; in Scorpenich- 
thys and Sebastodes it is a branch from intestinal artery,,). 
Mesenteric Artery. —The right and left gastric arteries 
respectively are essentially the same in all 4 genera. How- 
ever, since there are so many variations in the branching of the 
right gastric, the distribution of intestinal artery,,,, and the addi- 
tional air-bladder and anterior spermatic arteries in Sebastodes, 
it seems advisable to describe in detail the distribution of the 
mesenteric artery for each of the above genera. 
Mesenteric Artery in Scorpenichthys (P1. IV, fig. 29; a fork 
of Coe. Mes.A.).— After giving off the left gastric artery, the 
mesenteric artery separates into the r7ght gastric artery (fig. 
29, R.Gas.A.) and the intestinal artery,,,(fig. 29; Int.A.,)). The 
former gives off the left hepatic artery (figs. 29 and 30; L.- 
Hep.A.) and the latter follows along the stomach for a short 
distance, giving off a small branch to a smal] gland-like body, 
marked g, and the sflenzc artery (Pl. IV, fig. 29; Spl.A.), but 
before entering the spleen this vessel sends off a Posterior gas- 
