1905. | OF THE YELLOW-THROATED LIZARD. 265 
The left systemic arch gives off no branches at all that I could 
discover. 
From the right systemic arch (which joins the left at about 
the commencement of the lung) the two swbclavians (text- 
fig. 37, Sel., p. 263) are given off, nearly, if not exactly, opposite 
to each other. In front of this arises the vertebral artery (J.c.), 
which gives off an cesophageal branch before plunging into the 
thickness of the parietes. Behind the vertebral artery commences 
the series of intercostals. The first zntercostal artery arises just 
before the junction of the two aorte. It gives off a branch to the 
cesophagus. The next two intercostals have also cesophageal 
branches ; but it is to be noted that in all these the right inter- 
costal alone has this cesophageal branch. The left has none. The 
remaining intercostals have no cesophageal or gastric branches. 
Their arrangement is peculiar and agrees with that of the Skinks ; 
it differs from that of some other Lizards. 
In Tropidurus hispidus, for example, the regularly paired 
intercostals emerge from the dorsal aorta close to the articulation 
of successive vertebre, and plunge at once into the thickness of 
the parietes. 
In Gerrhosaurus the intercostal arteries emerge from the 
aorta at about the middle of each vertebra. In many cases, 
and the arrangement is roughly alternating, the intercostal of 
one or both sides divides at once into two branches; one of these 
plunges at once into the thickness of the parietes. The other 
passes obliquely forwards and runs superficially in close relation 
toarib. This, however, only occurs in the thoracic region, not in 
the lumbar. 
Precisely the same disposition of vessels is found in Huwmeces 
and some other Skinks, and the fact isa bond of union between 
the Gerrhosauride and Scincide. 
The next artery to arise from the aorta is a gastro-cesophageal 
(text-fig. 37, ws, g, p. 263, and text-fig. 38, ws, g', p. 264), which 
divides at once into a thin forwardly directed cesophageal, and a 
stout backwardly directed gastric. Between this and the large 
gastric artery (text-fig. 38, g°) are 6 pairs of intercostals. Two pairs 
intervene between this artery and that of the large intestine, and 
one pair between the latter and the artery of the small intestine. 
The ovarian and oviducal arteries present some features which 
are worthy of note. There are three pairs of oviducal arteries 
which are not symmetrical. The first of these is really mainly an 
ovarian artery, which gives off a thin and slender oviducal branch 
running along the anterior section of the oviduct. The two 
remaining oviducal arteries arise in common with an intercostal. 
They lie in front of the rectal artery. 
Venous System. 
Although the venous system of neither of the examples at my 
disposal was injected, most of the veins were beautifully displayed 
by their own turgescence. 
