446 MR. C. H. O DONOGHUE ON THE 
being termed the sub-clavian vein and, in addition, it is homo- 
logous with the similarly named vein in Kana *. 
1. The Lateral Abdominal Vein (Lateral Vein, Parker) [Pls. I. & 
TL., L.A.] is a moderate-sized vessel that runs immediately beneath 
the peritoneum along the ventro-lateral wall of the body-cavity. 
It originates as a continuation of the iliac vein on the dorsal 
side of the pelvic cartilage, across which it anastomoses with its 
fellow of the other side. Thence it passes forwards in the body- 
wall to the pericardio-peritoneal septum, in the wall of which it 
turns very sharply dorsalwards and slightly mesially along the 
posterior edge of the coracoid cartilage. A short distance along 
this it unites with the brachial sinus to form the sub-clavian vein. 
2. The Iliac Vein (Parker) [P1. I., Ll.] is a short vessel formed 
by the union of the femoral and cloacal veins on the inner side 
of the basipterygium towards its anterior end. It runs into the 
lateral abdominal vein on the dorsal surface of the pelvic bar. 
2.1. The Femoral Vein (Parker) [PI. L., F.] drains the major 
part of the pelvic fin and is situated laterally and slightly dorsal 
to the basipterygium. It passes across the anterior end of this 
cartilage, which is slightly notched to receive it, to unite with 
the cloacal vein. 
2. ii. The Cloacal Vein (Parker) [Pl. I., Cl.] lies on the inner 
side of the basipterygium, and is formed by the union of factors 
from the posterior and lateral walls of the cloaca and also from 
the inner side of the pelvie fin. 
it will be noted that the arrangement of the factors of this 
vein agree more. nearly with those described by Parker in 
Mustelus than with those figured by the same author for Rata 
nasuta, and those in: R. erinacea and R. levis according to Rand 
and Ulrich (14).,. ‘The additional factors in the skates are 
doubtless to be correlated with the greater relative size of the 
pelvic fin. A similar difference is found in the brachial veins ; 
only one such is present on each side in Scylliwm, while two are 
found in FR. erinacea and K. levis and three in Ff. nasuta. 
Further similarity with Mustelus is shown by the presence 
of a pelvic anastomosis between the lateral abdominal veins in 
Scyllium but not in the skates. 
3. The Rectal Vein [P1. I., Re.| isa small short vessel joining 
the anastomosis between the lateral abdominal veins in the middle 
line. Its branches form a fairly rich network of vessels spread 
over about the last one and a half inches of the rectum and the 
body-wall ventral to this. 
This vessel is not represented in Mustelus, where the posterior 
end of the rectum is drained by a fairly large proximal tributary 
of the cloacal vein on each side. It more nearly resembles the 
* Tn the tadpole the sub-clavian vein is formed by the union of the musculo- 
cutaneous, brachial, and the epigastric veins, the latter being homologous with the 
lateral abdominal veins. In the adult the two epigastrics are reduced to a median 
vein, the anterior abdominal, which acquires a secondary connection with the 
hepatic portal vein, though in certain abnormal specimens the primitive connection 
is retained (8). 
