BLOOD-VASCULAR SYSTEM OF THE LORICATI | I13 
All species of Sedastodes examined had a distinct renal por- 
tal system, which in the main resembled Ophzodon; however, 
the renal portal veins extend much further cephalad, there is 
always one or more posterior air-bladder veins emptying into 
the renal portal system, and there is no posterior mesenteric 
vein. The kidney itself differs considerably in shape from that 
of the other genera; while it usually occupies a large portion 
of the dorsal part of the short thoracic cavity, still a large por- 
tion of the organ is crowded cephalad into the two forks. The 
caudal vein (Pl. 1V, fig. 31; Cau.V.) after piercing the pos- 
terior dorsal side of the kidney continues cephalad along the 
dorsal surface of the kidney for some little distance as a renal 
portal vecn and not until the kidney forks does this vein sepa- 
rate into the renal portal vems (fig. 31, Ren.P.V.). These 
veins continue cephalad in their respective lobes until near the 
point of union of the cardinals with the jugulars, giving off 
numerous afferent renal veins, and the renal portal itself re- 
ceives the following vessels. First, the spermatic vern (fig. 31 ; 
Sper.V.), which is formed from the posterior union of the right 
and left spermatic veins. In its dorsal course about midway 
between the reproductive organs and the kidney it receives the 
urinary bladder vein (fig. 31; Ur.Bl.V.), and immediately be- 
fore emptying into the renal portal, a small swprarenal vern. 
Shortly after receiving the spermatic, the caudal or renal por- 
tal receives a rather large fostertor air-bladder vein (fig. 31; 
P.A.BI.V.), which arises from a regular network of vessels on 
the posterior end of the air-bladder. In the specimen from 
which fig. 31 was drawn, two smaller posterior air-bladder 
veins were also noticed; one of which terminated in the renal 
portal vein, and the other in the right cardinal. Usually, how- 
ever, there is but one posterior air-bladder vein, and it may 
empty into either the right cardinal or the renal portal vein. 
The right cardinal is almost identical to the similar vessel of 
the other genera, and a description of it is unnecessary. 
VIII. VASCULAR SYSTEM IN ANOPLOPOMA. 
Three specimens of this species were brought in by Chinese 
fishermen when this paper was about finished. All were in- 
Proc. Wash. Acad. Sci., June, 1905. 
