778 
ME. W. K. PAEKEE ON THE STEUCTUEE AND 
The broad roof-like frontal surface of the ethmoid (Plate LXXXIII. figs. 2, 4 & 5, eth.) 
ends in a long retral spur, which surmounts the olfactory grooves : there is no “ crista 
galli.” A deep chink on each side separates the aliethmoidal ( al.e .) from the aliseptal 
(al.s.) regions, and a lesser chink marks the posterior boundary of the alinasal ( al.n .) region. 
The diverging terminations of the alas nasi retain their primary form as the out-turned 
trabecular horns ; they closely embrace that azygous outgrowth of the trabeculae which X 
have called the “ prenasal cartilage ” (qt.n .) ; this snout-cartilage is now at its full size. 
In the under view (Plate LXXXIII. fig. 1) I have depicted the splints that show them- 
selves on the basal plane, whilst the lacrymals ( l .) and frontals (f) are merely indicated 
by a dotted outline. 
The superoccipitals (Plate LXXXII. figs. 8 & 9, s.o.) have nearly met above the 
foramen magnum (f.m .) ; the exoccipitals (e.o.) have enclosed the vagus (8), and are 
enclosing the ninth nerve (9) ; behind they mount over the posterior semicircular canal 
(jj.s.c.), and are spreading along the tympanic wings of the occipital cartilage. 
The occipital condyle (Plate LXXXII. fig. 8, and Plate LXXXIII. fig. 1, o.c .) has 
a piece of the notochord ( n.c .) projecting from its dimpled end; in front it ends below 
the basioccipital, which is under-floored, anteriorly, by the huge, expanding, almost 
coalesced basitemporals ( b.t .). 
On each side the lower edge of the squamosal (sg.) is seen dipping between the post- 
frontal and exoccipital outgrowths. 
The rostrum (Plate LXXXIII. fig. 1, r.b.s.) is blunt-pointed anteriorly; it lies on a 
somewhat higher plane than the basitemporals, and has lost its former distinctness and 
simplicity, having ossified much of the lower part of the basisphenoidal cartilage ( b.s .). 
But not only has this centre affected the overlying cartilage, it has grown into short 
wings between the heads of the pterygoids, forming the roots of the “ anterior pterygoid 
processes” and into huge pretemporal wings (the “posterior pterygoid processes”) 
(jp.r.jp.). The anterior pterygoid processes are capped with a cartilaginous plate (to 
be described anon), and the posterior wings have the “lingulae sphenoidales” as their 
cartilaginous or endoskeletal root: this will be dilated upon when the sections are 
explained. 
There is one more basicranial splint — the vomer ( v .) ; this is a very small style, at 
present emarginate anteriorly, and blunt behind ; but it changes its shape afterwards ; 
it is developed in the same general tract of subcutaneous tissue as the “ rostrum.” The 
rest of the base of the cartilaginous axis is enveloped in soft fibrous stroma, which is 
only subject to ossification from lateral symmetrical points. 
These symmetrical ossicles are developed in the subcutaneous stroma of the facial 
laminae; they are the premaxillaries {jp.x.), maxillaries (m.x.), jugals (j.), and qua- 
drato-jugals (gj .) : all these have acquired considerable density since the last period. 
The palatines (joa.) are thoroughly ossified, and the pterygoids have lost most of their 
simple cartilaginous pith ; a hyaline plate abuts against the anterior pterygoid processes, 
and the capped, unossified posterior end is acquiring considerable density. 
