106 
MR. W. K. PARKER OK THE STRUCTURE AND 
Here tire form of the frontal is well seen, and can be compared with the same 
view in the Tcttou (Plate 6, fig. 3). Here the swelling in front of and above the 
orbit makes the skull at this part almost as bulky as it is in the region of the ripper 
fontanelle (fo.), and in this side view the frontal seems to be made of two parts, 
separated by a deep, oblique valley. The supraorbital ridge does not extend so far 
backwards as the wall-plate of the bone, which runs back there, and notches the fore 
edge of the parietal, on the lower part of the coronal suture. Thus the parietal is of 
a more normal size, and the squamosal does not dominate this part of the skull as in 
Pangolins and Sloths. 
Below the notch, the parietal (p. ) forms a round lobe which rests upon both the cartila¬ 
ginous top of the orbitosphenoid ( o.s .), and the wholly ossified alisphenoid (a/. 5 .), and 
further back it forms the upper part of the temporal fossa, its whole lower edge being 
somewhat concave, and the outline both there and behind is somewhat emarginate, to 
receive the arched margin of the squamosal and intraparietal {i.pd). The latter bone 
is about one-third the size of the parietal, and it reaches back over the outer edge of 
the unossified part of the occipital plane. 
The squamosal (sq.) is quite normal, it is much smaller than that of a Sloth or 
Pangolin, and much larger than that of Cycloturus. 
The temporal squama has an arched upper edge ; the hind margin of the bone is 
broad and emarginate; the outer face is moderately convex for a moderate pneumatic 
cavity over the drum cavity, and both there, wdiere the glenoid cartilage (gl.f.) 
has grown on to it, the margin is notched; the zygomatic spur is well developed. 
From the peculiar manner in which the overlappings, or imbrications, of the parts that 
form the inner wall of the orbit are developed, the mind at once refers to the skull of 
the Insectivora. The orbital plate of the frontal (f ) is a thin hollow shell of bone, 
the hind margin of which is one large crescentic notch, inside which a semicircular 
tract of the semiosseous orbitosphenoid is exposed; the optic nerve (II.) escapes 
through the proximal part of the bony base of this tract, and the ophthalmic nerve 
(V 1 .) re-enters the skull near the junction of the bone and cartilage in that plate. 
The rounded corners of both the frontal and parietal bones overlap the cartilage 
postero-superiorly, and, behind, its cartilaginous part is notched in the same crescentic 
manner as the orbital plate of the frontal, and is then overlapped by the semicircular 
fore edge of the alisphenoid ( al.s .), which round edge is nearly parallel with the hind 
margin of the orbital plate of the frontal. This outstanding fore edge of the ali¬ 
sphenoid forms the hinder boundary of the sphenoidal fissure (V 1, 3 .); its inner boundary 
is formed by the orbitosphenoid {o.s.). -The palatine {pa.) crops up in the antero¬ 
inferior part of the orbit; the pterygoid {pg.) can be seen below the jugal arch. 
Below the tegminal notch of the squamosal the tympanic (<a.ty .) and manubrium 
can just be seen. The supraoccipital bone ( s.o.) bends down behind the intraparietals, 
behind which the thick wide convex unossified part is seen. Behind the lower lobe 
of the end of the squamosal a small convexity is seen; this is formed by the hori- 
