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 jMsferior. — It is interesting to note that Gerrhosaiorus 

 agrees with Tiliqua 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 Scincidse. As in Tiliqua 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 junction 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. T 

 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 thii-d 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 diametei- 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 Chainceleon and 

 PygojnhS t. 



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 on a 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 biunch, which appears to me to be the 

 equivalent of the lateral abdominal vein of other Liza,rds. Its 

 shortness in Gerrhosattrus 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 Beddavd, P. Z. S. 1904, vol. i. p. 445, fig. 93. 

 t See P. Z. S. 1904, vol. ii. p. 15, fig. 4. 



