TOG 
MR. W. Iv. PARKER OK THE STRUCTURE AND 
They are now 'perfectly distinct from that floor, and a little pressure serves to shell 
them out under the cover-glass ; this causes no tearing of the tissue. The large 
fenestra ovalis (fo.) is as wide as one of the canals, and as long as the diameter of 
an ampulla; it lies along the middle, obliquely parallel with the horizontal canal ; 
its antero-internal edge is double, being composed of both floor and capsule; the vesti¬ 
bule swells out on its inner side in a crescentic manner. From the inner edge of each 
capsule, above (fig. 6), there is a little tract of new roof-cartilage, which will finish 
the occipital arch. The basis cranii in the orbital region widens a little forward ; the 
trabeculae (tr.) occupy nearly a third of its breadth; the trabeculae have met in the 
ethmoidal region, and are becoming fused together ; the line of fusion is nearly equal 
to the intertrabecular space, behind ( i.tr .), which is now half filled in with new cartilage. 
In front, the trabeculae are free, diverge at more than a right angle, and curve out¬ 
wards ; these are the horns of the trabeculae ( c.tr .). Newer cartilage has appeared in 
several places ; laterally, the trabeculae have grown into orbital walls, and these walls 
are growing over the roof a little, especially in the ethmoidal region (fig. 6). Out¬ 
side, in front of these rudiments of the “ tegmen cranii,” the “ ethmoidal wings ” have 
appeared, embracing the nasal sacs (n.r.). 
Between these sacs the trabeculae are very thick, where they are narrowest, and 
then suddenly expand into the “cornua.” These latter, or their inner edge, are 
developing a thin, crenate expansion, ready to finish the nasal floor. The trabeculae 
are most compressed where they form, below, the semi-circular inner boundary of the 
internal nostrils ( i.n .). Over the sac, right and left, there is a small cartilage, like the 
valve of a small Entomostracan, attached to the ethmoidad wing : this is the nasal roofi 
cartilage (first “ paraneural,” n.r.) ; here it is more distinct than usual—more than I 
have ever seen it in this group. 
The huge suspensorial bands reach by their distal condyles (<q.c .) in front of the 
nasal sacs, whilst, behind, they curl themselves up against the intruded auditory 
capsules (au.), and bend suddenly upwards as they pass inwards, to form the narrowed 
(but really broad) pedicle (pel.).* 
At this part the cartilage rises so high that it would seem to form the counterpart 
of the “ascending process ” of the Urodeles, but it drops again before it passes into the 
trabecula, and although riding over the vidian nerve (YII 1 .) it passes under the 5th 
(figs. 6, 7, V.). This thick high part will be further outwards, afterwards, and will 
form the otic process ( ot.p> .). In front, the quadrate passes inwards as a broad lamina 
from the saddle-shaped condyle, and grows into a hook—the pre-palatine rudiment 
(fig. 7) bounding the nasal passage, below, as the ethmoidal wing does, above. 
The pterygo-palatine conjugational band is short, wide, and out-turned; on it, 
as yet, I see no definite rudiment of the post-palatine process. Over it, from the 
large projecting sulcate condyle for the hyoid ( hy.fl ’.), the orbitar process (or.pt.) grows ; 
* The pedicle lies on a higher plane than the pterygo-palatine band; it is, like the ribbed edge, and 
orbitar process, a temporary tract of the suspensorium. 
