CIRCULATORY SYSTEM OF ELASMOBRANGHS, 437 
definitive posterior cardinal sinuses. The second divides into 
two parts—an anterior which gives rise to the hepatic portal 
vein, and a posterior which acquires a connection with the outer 
side of the kidney loop and forms the renal-portal vein. 
Text-figure I 
Su. 
NHS. 
Rea 
sate 
Diagram of the vessels in a fairly late embryo of Seyllium canicula. 
V.C.L. Vena capitis lateralis. S.I. Sub-intestinal vein. V.I. Inter-renal vein. 
For explanation of other lettering see p. 454. 
Adopted and modified from Rabl (11), 
According to Rabl (11), quoted also by Hochstetter (4), the 
sub-clavian vein is described and figured as opening into the 
posterior cardinal sinus, whereas in Seylliwm, in Mustelus, and 
in the skates, this vein opens into the ductus Cuvieri, and 
in the two former it opens into the ductus between the 
point of entry of the anterior cardinal sinus and the sinus 
29% 
