GIGANTIC LAND-LIZARD FROM AUSTRALIA. 
1043 
On the right side of the skull, inches of the outer wall (ib., oc) extends behind 
the supra-temporal horn-core (b). The broken edge of this portion of skull gives \ inch 
thickness of rather compact bone, increasing upwards to 1^ inch, with a finely cancellous 
texture occupying the middle two-thirds. The hind broken margin of the upper wall 
of the skull thins off to 2 or 3 lines. From the under surface and mid-line of this 
border a septum (Plate 37, fig. 1,7') descends for about the extent of an inch, answering 
to that which similarly descends from the line of the sagittal suture to articulate, in 
Chelone, with the subjacent occipital spine. On each side of this indication by the 
medial septum of capacious temporal fossse the inner smooth compact surface of the 
bone is largely and deeply excavated. 
The nasal aperture (Plates 37 and 38, fig. 1, ol) is overhung by the coalesced nasal 
bones (ib., 15 ) which project about H inch in advance of the premaxillary (ib. ib., 22 ). 
The aperture is 2§ inches in breadth, 1 inch 2 lines in height, partially bisected by a 
septal process (n) of the premaxillary, which rises towards, but does not meet, the 
corresponding thinner septal process from the under part of the nasal. 
The premaxillary (ib., 22 ) is continued from the nostril downward, with a slight 
backward curve, about 2 inches beneath the olfactory cavity, the floor of which curves 
downward at the outlet, with little mark of boundary, upon the fore surface of the 
premaxillary. 
All sutures are obliterated : at least I have not been able to determine any, satis¬ 
factorily, in the portions of the cranium transmitted. 
A shallow channel (Plate 38, figs. 1 and 2, on), \ inch broad, is continued from the 
nostril to the orbit, dividing, as it seems, the nasal bone ( 15 ) from the maxillo- 
premaxillary ( 21 , 22 ) on each side of the outer surface of the skull, the channels 
converging as they advance to the sides of the nostril. 
The lower border of the maxillo-premaxillary (ib., fig. 3, 21 , 22 ) is subtrenchant, 
convex forward; the breadth of the preserved part across the ends of the semicircle, 
beneath the orbits, is 6| inches. An irregular notch at the middle of the fore part of 
the edentulous border (ib., fig. 2, 22 ) seems due to accident. The sides as well as fore 
part of this evidence of the upper jaw curve downward and inward. 
The upper surface of the nasal (is), supporting the surface for the horn-core (cl), 
is broad, flattened, but laterally bends down somewhat abruptly to form the antorbital 
side-wall of the nasal cavity. The platform supporting the front horn (cl) shows great 
thickness and strength. 
The extent of skull between the nostril and orbit is 2 inches. The preserved 
border of the orbit (Plates 37 and 38, fig. 1, 0 ) is sub-semicircular in shape. Its upper 
boundary extends from the orbito-nasal groove obliquely upward and backward for 
the extent of 2 inches; the hind boundary then bends abruptly downward and rather 
backward; the lower boundary is broken away on both sides of the skull; about half 
of the orbital floor is preserved on the left side; rather more of the roof (Plate 38, 
fig. 3, o', o') is preserved on both sides. There is a feeble prominence at the middle 
6 s 2 
