610 
MR. W. K. PARKER OK THE STRUCTURE AND 
narrow oblique floor bands (n.f.) ; there is only so much of the wall as serves to hold 
the inferior turbinal (i.tb.) in place. 
The hemispheres (C 1 ") are cut through them fore part, over the origin of the 
olfactory crura. (See Plate 43, figs. 1 and 7,1.) 
There is no cartilage either in floor or roof at this part of the cranial cavity, with 
the exception of a narrow band on each side the upper inturned part of the antorbital 
wall (p.p.) and the narrow bands inside the floor (n.f.). (See figs. 9, 10.) 
If we compare this figure with those of the perfect skull (Plate 42, figs. 1 and 3, 
f, pf, rnx.), we shall find that the maxillary reaches the frontal, and the prefrontal 
crops up close behind the highest part of the large facial plate of the maxillary. 
The next two sections (9th and 10th, figs. 9, 10), are through the cranio-facial 
fenestra (see Plate 43, figs. 1, 2, c.f.f), so that the septum—“ meso-ethmoid —is now 
seen as two rounded parts. 
In both, the prefrontal has gained the roof, and wedges in between the frontal and 
maxillary, and the thick frontals are now growing into the side of the skull, resting 
obliquely on the prefrontal plate. 
Below, the vomers (v.) are still large, and the maxillaries (mx. ) form a strong wall, 
and a good piece of the floor. 
In the 9tli section the antorbital plate (p.p.) or “pars plana” is cut through so as 
to give a zig-zag band of cartilage; but if we compare this with figs. 8 and 10 we 
shall see its meaning. 
This section shows well that the antorbital cartilage or bach wall of the nasal 
capsule grows inwards and forwards against the septum nasi, but is soon reduced to 
a narrow band in the inner part of the floor, which band runs forwards to the 3rd 
section (fig. 3, n.f). 
The large leafy antorbital wall is a curved axe with a short helve ; this helve which 
is pedate, rests upon the palatine plate of'the maxillary, with the “toe” inwards and 
backwards, and the “ heel ” outwards and forwards. 
That this cartilage should be united to the nasal wall by a narrow isthmus, and 
should rest upon the palatine plate of the maxillary, so accurately turning its “ toe ” 
inwards and backwards, and its “heel” outwards and forwards, is quite normal and in 
accordance with the morphological laws governing these things. 
This cartilage is well known to the student of the “ Ichthyopsida,” and once known 
well in them can be interpreted and understood under all sorts of forms and disguises; 
it is the rudiment of the 2nd pree-oral or palatine arch, and is indifferently called the 
“antorbital” or “ etlnno-palatine ” cartilage; its main splint or investing bone is the 
maxillary, which bears the same relation to it that the “ dentary ” does to Meckel’s 
cartilage—the main splint, and the axis, of the mandible.* 
* I was once, fox’ a time, sceptical as to tlie independent existence of this arch; the Tadpole, in which 
it is suppressed, for a time, making me waver. Professor Huxley also, for a time, strongly protested against 
its existence. Now, howevei', besides my own cai’efully long-linked chain of moi’plxological details, I can 
