716 
PROFESSOR T. J. PARKER ON THE 
the underlying muscles ; it receives vessels from the neighbouring parts, as well as the 
lateral cutaneous vein {infra, p. 721), and, passing forwards and inwards, discharges 
into the cardinal sinus. 
The oesophageal veins. 
These form a close plexus, resembling that of the mammalian gravid uterus ; they 
open on each side, by small apertures in its inner wall, into the cardinal sinus. 
C. System of the Lateral Veins. 
6. The Lateral Vein. 
(Anterior part only.) A large vein from the abdominal muscles and side of 
the fish, Monro (16). 
Gros vaisseau lymphatique sous-peritoneal, vaisseau lateral, Robin, quoted 
by Milne Edwards (15). 
Llio-hcemorrhoidal plus Epigastric vein, Parker (21 and 23). 
Lateral vein, Parker (22). 
The lateral vein (Plate 34, figs. 1-3 ; Plate 35, figs. 9 and 10 ; Plate 37, figs. 20-24, 
Lat. V.) is a vessel of considerable size lying in the side wall of the abdomen imme¬ 
diately external to the peritoneum, and passing from the level of the pelvic fin 
forwards and upwards to the level of the pectoral. Posteriorly it unites with its 
fellow across the dorsal face of the pubic cartilage (figs. 1, 3, and 24); anteriorly it 
turns inwards or towards the middle line, and then forwards, outwards, and upwards, 
to open into the precaval sinus {supra, p. 710, figs. 1, 2, 9, and 19). It receives veins 
from the abdominal walls, as well as from the pectoral and pelvic fins {infra, p. 717), 
and anastomoses with the anterior ventral cutaneous vein (p. 720). 
The anterior moiety of the lateral vein of the Skate is figured by Monro (16, 
Plate IIP), who, however, only traced it a short distance backwards. Robin* seems 
to have been the first to notice the veins in their entirety, but he apparently missed 
their connexion with the brachial and femoral veins, as well as with the precaval 
sinus; he also originally described them as lymphatics, but afterwards, finding them 
to contain blood, was led to consider them as veins.! They were re-discovered by 
myself in the Skate (21), and were subsequently found to exist in Scymnus, Acanthias, 
Mustelus, and Chiloscyllium (22). In recording their presence in the last named 
genera I remarked that, although I had found no account of them, it was difficult to 
believe such large vessels to have escaped notice; it had not occurred to me at that 
time to consult the section on the lymphatic system in Milne Edwards’s “ Lecons,'’ 
and no mention of the lateral veins is made under the head of the venous system. 
* Robin, Revue Zoologique’ de Guerin,” 1845, p. 225.—Quoted by Milne Edwards (15, p. 477). 
t Robin, “Note sur le systeme sanguin et lymphatique des Raies et des Squales,” ‘ L’lnstitut,’ yoI. 13, 
1845, p. 452.—Quoted by Milne Edwards (15, p. 472). 
