224 MR. W. K. PARKER ON THE STRUCTURE AND 
non-persistent sutures is very strong, as in the Salamander’s skull. The hinder outline 
of the parietals and interparietals, together, is a very neat semi-circle, just flanked, 
and made to look irregular by the partial view, in this aspect, of the squamosal, 
auditory, and supraoccipital bones. 
In the side view (fig. 3) the parts just spoken of as flanking the great roof-bones, 
come fully into sight, as also the bones of the upper face, so imperfectly seen from 
above. 
Behind the deflected snout (al.n.), the strong, oblique, unciform premaxillary facial 
plate (px.), is seen with its sharp and rather large teeth ; over it the nasal (n.) is seen 
somewhat ; the maxillary (mz.) is nearly half the length of the whole bony skull, and 
is a notable prophecy of what this bone, with its heavy burden of teeth, will become 
in the great herbivorous Eutheria; from its rounded edge, closely fitted to the 
premaxillary, it runs backwards as far as the coronal suture, ending there as a flat, free 
jugal process. A low triangle, its posterior edge is shorter than its anterior, and 
that is the most irregular. That irregular edge bounds the front of the badly enclosed 
orbit ; near its upper part, the squamous, perforated lachrymal (/., /c.) fits into a deep 
recess, and below this the great infraorbital foramen (V*.) runs on, forwards, as a large 
groove ; it is very feebly finished, outside, by an arched bar which articulates with the 
lachrymal. Behind that suture the maxillary is seen as a large rounded lobe of bone, 
the outer alveolar wall of the two last molars, and the jugal process, ali in one tract. 
Even now the frontals and parietals have separate convexities, that of the former is 
the higher of the two. The orbital plate is notched where the Ist branch of the 5th 
nerve (V1) re-enters the skull, and there the frontal, parietal, orbitosphenoid and ali- 
sphenoid, all approach each other. In the temporal region the parietal swells over the 
squamosal, whose seale-like temporal flange overlaps the lower edge of the former; 
it is sharp at its fore corner, where it lies on the projecting alisphenoid, and it turns 
upwards in its post-temporal region, to bind, tightly, between the parietal outside, and 
above, and the auditory capsule within, and below. The oblique retreating front 
margin of the squamosal is notched, and meets its outer oblique edge at an obtuse 
angle, beyond the glenoid cavity (gl.c.); it scarcely projects at all as a jugal process. 
The lower postglenoid facet binds upon the canal-region of the auditory labyrinth 
by its oblique, toothed, and notched posterior margin. This side view shows the 
interparietal (7.p.), the pterygoid hook (pg.) and the annulus (aty.). At present, 
therefore, the temporal fossa is badly enclosed, and the sagittal and lambdoidal crests 
have no existence. 
In this same side view the mandible is seen as an almost crescentic bone ; the axis 
of the ramus and of the high coronoid process (c p.), being coincident. The three 
processes are almost equal, for the smallest of the three, the angular (ag-.p.) is larger 
than it seems to be as seen from the side; seen endwise (fig. 34) it has a thick 
limbate inturned edge, and is manifestly Marsupial.. The condyloid process (cd.p.) 
is oval, transverse, and has the narrow end inwards. The dentary canal can be seen 
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