28 MR. W. K. PARKER ON THE STRUCTURE AND 
the lesser bulb forming the mastoid (opisthotic) region (op.) are all displayed ; in the 
latter, the ampulla of the posterior, and the end of the horizontal canals (p.s.c., the 
latter is not lettered ; it is in fig. 4) shine through the cartilage. 
In the interspaces between these large ear-balls and the hind skull, the vagus and 
glossopharyngeal nerves (X., IX.) emerge, partly through the fissures, and partly in 
enclosing cartilage. The internal carotids enter the cranium between the cochlez 
and the basisphenoidal beam (b.s.). Under the tegmen the facial nerve (VII.) makes 
its first exit, and then burrows the cartilage again, over and behind the junction of the 
epihyal (e.y.) with the capsule. Postero-externally, the auditory capsule shows 
two large perforations, the foremost of these lies inside the hind part of the tegmen, 
and opens into the vestibule ; this is the fenestra ovalis (fs.0.) ; the other, the fenestra 
rotunda (/-7.), opens into the cochlea (ch/.) in the postero-lateral face of the first turn 
of the three-coiled “ helix.” 
The basis cranii for the rest of the skull is half cartilage, spheno-occipital, and half 
bone, basioccipital (b.0.) ; this “ centre” is oval, but truncated in front. Outside it, at 
a distance equal to its width, right and left, the hypoglossal nerve (XIL.) burrows the 
solid cartilage of the base of the exoccipital wall. Behind this, at a like distance, the 
semi-oval condyles are seen (0c.c.), margining the huge sub-circular foramen magnum 
(f-m.), at its antero-inferior edge. The paroccipital thickenings outside the condyles 
are not large ; the exoccipitals (e.0.) are beginning to harden the walls ; and over the 
foramen magnum two tracts of bone are seen, the two supraoccipitals (s.0.). 
In the upper view (Plate 2, fig. 7) the parts seen are mainly superficial ; the huge 
occipital roof, with its two ear-shaped bony centres (b.0.) are seen behind the great 
fontanelle (fo.). In front, the roof of the alinasal region (al.n.) is but little shown, on 
account of the very forward position of the nasal bones (n.). These bones are nearly 
oblong, they project at the mid-line,in front, and are cut away, equally, behind; then 
they widen slightly. This region of the skull is like the narrow end of a gourd, and 
the rest may be likened to its bulbous part. 
The frontals (f-), together, give a broad-waisted outline, being gently pinched in 
over the orbits; the parts there marked off are each as large as the parietals (p.), 
behind. Outside, the maxillaries, jugals, and squamosals (mz., j., sq.) are just seen ; 
the lacrymal (/.) also slightly. The fontanelle (/v.) is still large and cruciform; it is 
pointed in front, and dilated behind. 
But the side wew (Plate 2, fig. 8) brings out the form and relations of the investing 
bones best ; it also displays more of the inner skull; and with it the arches of the 
face are given. In front the alinasal cartilage and external nostril (al.n., en.) are 
seen ; between the frontal and maxillary, the wall of the upper turbinal (v.¢b.), and 
inside the orbit, at the bottom, in front, the wall of the middle turbinal (m.tb.). 
Below the squamosal we see part of the capsule of the ear (ch/.) where the tympanic 
should be; behind the squamosal, the opisthotic region with the enclosed posterior 
