BLOOD-VASCULAR SYSTEM OF THE LORICATI 95 
did these 2 veins leave the pectoral fin canal in the same places ; 
in fact, they were not the same in the 2 different fins of 
the same fish. In the fin from which fig. 14 was drawn the 
dorsal branch left between the seventh and eighth rays, count- 
ing dorso-ventrad, and the ventral branch left in the neighbor- 
hood of the fourteenth ray. Each of these branches proceeded 
dorsad, for some little distance, along the inner surface of the 
superficial pectoral adductor muscle, and each branch received 
numerous smaller branches from the superficial and profundus 
adductor muscles. Uniting on the level with the scapula fora- 
men they form the internal subclavian trunk, which continues 
dorsad behind the subclavian artery. Shortly before the kidney 
is reached it curves caudad, and passing between the first few 
spinal nerves and the superficial adductor muscle, pierces the 
ventral surface of the corresponding fork of the kidney. Once 
within the kidney the internal subclavian rapidly decreases in 
caliber, by sending off branches that break up into capillaries, 
which finally reach the cardinal through the renal veins. 
The vein designated as the external subclavian or subclavian 
veins, (Pl. Il, fig. 14; Sub.V.,,)) has its origin from the super- 
ficial and profundus pectoral abductor muscles, on the outer 
surface of the pectoral arch. Coming through the scapula 
foramen, cephalad of the external subclavian artery, it re- 
ceives a branch from the profundus adductor muscle, and then 
runs for a short distance below and behind the precaval vein, 
where it receives the vein designated as the subclavian vein.) 
(Pil teste oub.V..4)) “his vein takes its' source from, 2 
branches, one coming from the ventro-cephalic portion of the 
profundus abductor muscle, and the other from the similar part 
of the profundus adductor muscle. The former penetrates the 
coracoid foramen, and unites with the latter in forming the main 
subclavian vein,,), which passes dorsad along the inner surface 
of the profundus adductor muscle. Leaving this muscle, 
subclavian vein,,, unites with the external subclavian vein to 
form the subclavian sinus (Pl. Il, fig. 12; Sub.S.), which 
empties into the sinus venosus directly behind the precaval vein, 
but before uniting with the external subclavian, it receives a 
vessel formed from a branch from the clavicle and the stevno- 
hyotdeus vein (Pl. Il, figs. 12 and 14; Ster.V.). 
