BLOOD- VASCILAR SYSTEM OF THE LORICATI 1 23 



scribed under Ophiodon, or they may arise from the dorsal 

 aorta as in Auoplopoma. In the case of Auoploponia a rather 

 large hypobranchial artery is given off, which anastomoses with 

 the anterior ventral artery, and the right hypobranchial sends 

 off the posterior ventral artery for the ventral fin region. The 

 cceliac artery always supplies the pyloric caeca. With Ophio- 

 doiiy Scbaslodcs, and Anoplopoma it is the source of the left hepa- 

 tic artery, and in Ophiodon, Hcxagrammos^ and Anoplopoma 

 it gives off intestinal artery,2). From the mesenteric artery, in- 

 testinal artery(i), the splenic and 2 gastric arteries have their 

 origin. In Hexagi'mnmos and Scorfcenichthys the right gastric 

 is the source of the left hepatic artery, and in Scbastodcs it is 

 the source of the right spermatic and the anterior air-bladder 

 arteries, the left spermatic artery coming from the left gastric 

 artery. In ScorpcBuichthys the entire intestinal supply comes 

 from the mesenteric artery. 



Swnmary of the Veins. — The jugular and its branches are 

 essentially the same in all the species studied, receiving the 

 mandibular, hyoidean, maxillary, orbito-nasal, ophthalmic, eye- 

 muscle, and encephalic veins. In addition to the main inferior 

 jugular and the left fork there are additional veins from the 

 pharynx region in Sebastodes, Scorpcenichthys, and Anoplopoma^ 

 which empty into the precava. Considerable variation is shown 

 in the subclavian veins. There is always an external and an 

 internal subclavian, and in Scorpcenichthys there are several 

 internal subclavians. Ordinarily the internal subclavian breaks 

 up in the corresponding fork of the kidney, and the external 

 subclavian empties into the precava, but in Scoj'pcenichthys the 

 external subclavian also breaks up in the kidney, while in 

 Anoplopoma the external subclavian appears to penetrate the 

 scapula foramen with the corresponding artery, uniting with the 

 internal vein to form a common trunk, which breaks up in the 

 kidney. Usually there are 2 ventral veins of equal size, but 

 in Ophiodon one of them is often much the larger, draining the 

 entire ventral fin region. There is always a distinct renal portal 

 system. The caudal vein arises in the tail and passing forward 

 in the haemal canal below the aorta, receives the neural and 

 haemal veins, and upon entering the kidney, usually, bifurcates 



