178 
ME. W. K. PAEKEE ON THE STETJCTUEE AND 
and the subnasal (s.n.l) at its greatest width. At the outer angle, below, the maxillary 
[mx.) has been cut through, and mesiad of it the vomer (v.) at a great distance from the 
palatal processes of the premaxillaries (see also Plate IX. fig. 2). Here we see that 
the septum nasi ( s.n .) gives off three pairs of alse — the aliseptal above, the subnasal below, 
and between them, near the top, another, which passes downwards and outwards, forming 
a floor to the external nostril [e.nfi The alinasal is at this part fixed, although it is free 
behind ; and it is continuous with the intermediate cartilaginous ala, which may be called 
the “transeptal lamina.” Although there is no free “alinasal turbinal,” there is never- 
theless a fixed lamina answering in some degree to it (compare Plate X. fig. 3, al.n ., 
t.s.l., with that of the Tinamou , ‘Skull of the Ostrich-tribe,’ plate 15, fig. 11, n.t.b .); 
for the “transeptal lamina” splits, when nearly half across, into two nearly equal layers, 
both of which terminate externally ; the lower of these is evidently t\xe fixed counterpart 
of the free “ alinasal turbinal” of the Bird. 
That the valvular processes are free “ horns ” is evident from this view, which shows 
the valvular process of the external nostril (v.e.n.), and the inner valvular process of the 
internal nostril (i.v.jj.), both quite separate as sections. 
A section made through the anterior margin of the annular ethmoid (Plate X. fig. 7, 
eth.) shows the perfect simplicity of the true olfactory region, which is of great width, 
and is closed externally where the upper and lower alee pass into the “ superpalatal ” 
(s.pa.). Above (Plate IX. fig. 6, s.pa., al.efi the “ala,” now “ aliethmoid,” passes 
directly into the “ superpalatal ” without any notch ; but below, the “ subnasal lamina ” 
becomes narrow, and has a deep notch separating it from the thin lower flap which 
thickens to pass into the “superpalatal” (Plate IX. fig. 7). The ethmoidal roof, even 
a little in front of the annular bony mass, is the part from which the upper turbinals 
arise in higher types ; the foundation for the middle turbinals must be sought for in the 
prefrontal wall on the posterior surface of the two laminae which pass into the “ super- 
palatal.” The sectional view does not show this, for the razor passed immediately in 
front of it ; but in the bird’s-eye view (Plate IX. fig. 6, jo.r.f.) the back of the folded 
lamina is seen, and on the postero-superior surface, which is bevelled, sloping down to 
the orbit, there is a very notable prefrontal patch of endostosis, the morphological 
counterpart of the “ prefrontal ” of the Teleostean fish, the Crocodile, and the Monitor, 
the “antorbital” of the Bird, and the “pars plana” of the Mammal; this would be the 
root of a “ middle turbinal,” if such there were. 
The “notch” between the “subnasal” and the foundation of the palatal pier is cut 
through in the section (Plate X. fig. 7, no .) ; mesiad of this notch the dentigerous part of 
the vomer (v.) is severed, and outside it the thin ectosteal palatal (pa.), whilst on the roof 
is seen the nasal ( n .). The bony substance of the ethmoid is seen both above and below 
the section, which has been made through the pointed middle portion (Plate IX. 
figs. 6, 7, eth .) ; this is the part where the “ perpendicular ethmoid ” ends and the proper 
“ septum nasi ” begins (see Plate VII. fig. 11, p.e.). A section made immediately behind 
the olfactory passages (Plate IX. fig. 8, 1) shows the fossae in which the “rhinencephala” 
