266 ON THE ANATOMY OF THE YELLOW-THROATED LIZARD. [June 6, 
There are many differences in detail between the venous system 
of this lizard and that of other genera. 
Vena cava posterior.—It is interesting to note that Gerrhosaurus 
agrees with Zuliqgua in that the left vena cava posterior is very 
much thinner than the stout right vein. This is another of those 
numerous though individually perhaps small points of likeness 
between the genus whose anatomy is dealt with in the present 
communication and the Scincide. As in Z%liqua also *, the left 
cava or vena renalis revehens lies to the left side of the mesorectum 
and the right vein to the right side of that mesentery. The left 
vena revehens is large where it receives the three or four veins 
arranged in a fan-like fashion from the left ovary ; behind this 
point it dwindles immediately but can be easily traced to the 
kidney, where it becomes enlarged at its jnnction with the right 
vena renalis revehens. 
The left vena renalis revehens receives two intercostal veins 
before the ovarian veins join it, and on the right side also I 
observed two intercostals. I could only observe one, and that a 
slender, oviducal vein joining the left vena renalis revehens. J 
feel convinced, however, that no veins from the oviducts join the 
afferent renal veins, as is often the case in Lizards. The reason 
for this in the present species may be that the kidneys are 
unusually far back. 
Afferent Renal Veins.—'The caudal vein reaches the kidneys as 
an undivided vein. It runs between them and receives a cloacal 
vein before dividing. Immediately after division each half receives 
another cloacal vein. The cloacal artery runs exactly at the 
point of division between the two afferent renals. At about the 
end of the first third of the kidney each renal afferent vein turns 
at right angles and runs superficially over the kidney, giving off 
a large branch to the kidney itself at about the middle of the 
transverse diameter of that organ. There is no sign of any 
forward continuation of the renal afferent vein beyond the 
anterior border of the kidney such as occurs in Chameleon and 
Pygopus *. 
Where the renal afferent vein reaches the border of the hind leg 
it receives three veins, two from the hind limb and one from the 
median dorsal parietes. It there runs directly forwards parallel 
with the kidney, and ona level with the anterior end of that gland 
receives the femoral vein, and a small parietal on the opposite side 
which crosses the epigastric artery. The vein then continues its 
straight course forward,and before bending inwards and downwards 
to follow closely the inner margin of the fat-body gives off a short 
forwardly directed branch, which appears to me to be the 
equivalent of the lateral abdominal vein of other Lizards. Its 
shortness in Gerrhosaurus contrasts with its length in Tiliqua. 
Hepatic Portal Veins——The mode of entrance of the conjoined 
intestinal portal and anterior abdominal and of the epigastric vein 
* See Beddard, P. Z.S. 1904, vol. i. p. 445, fig. 93. 
+ See P. Z.S. 1904, vol. ii. p. 15, fig. 4. 
