DEVELOPMENT OF THE SKULL IN THE MAMMALIA. 219 
relative development. The premaxillarics and maxillaries (px., mx.) are not well seen 
in this view. 
In the side view (fig. 3) the premaxillaries (pa.) are of the average size, and show 
a diamond-shaped oblique facial plate, which wedges in between the nasal and 
maxillary on each side. The maxillaries (ma.) are nearly half the length of the whole 
bony skull; the postero-superior angle runs somewhat into the orbit, and inside this 
process, and the one below it, the small lachrymal and its canal (1., dc.) are seen. That 
space is triangular, but under the sharp style that bounds it below, there is a deep 
chink along which the maxillary nerve (V*.) passes; it is unprotected on its outer 
side ; behind this chink the general alveolar roof runs for a considerable distance. 
The frontals (f.) have a thick supraorbital edge, and a large concave orbital plate. 
The growing parietals (p.) run forwards obliquely under the postorbital edge of the 
frontals, just meeting the upper and front angle of the alisphenoid (al.s). Thence, 
each parietal runs backwards to the antero-external edge of the azygous interparietal 
(i.p.); the obtuse re-entering angle formed by their junction exposes the huge 
auditory capsule. 
There are no jugals; each squamosal (sqg.) applies its small squamous plate over 
about a third of the lower edge of the parietal, rather in front of its middle. The 
jugal process does not reach so far forwards as the squamous; it only serves to 
carry the glenoid facet (gl.c.); the postglenoid process is very small, and the post- 
temporal plate small; its sharp hinder angle reaches half-way over the horizontal 
canal (h.s.c.) Under the squamosal the annulus (q.ty.) is just seen, and the pterygoid 
(pg-) with its cartilage (pg.c.) behind the alveolar angle of the maxillary (vu..). 
The lower jaw (d.) is well formed, and most of the cartilage on its three processes is 
ossified. The coronoid (c.p) is twice as prominent as the angular (ag.p.), and the 
condyloid (cd.p.) is rounded, and definitely marked off by a neck. The splenial region 
is seen in this inner view to be deficient inside MeckeEt’s cartilage (mk.), (a part soon 
to be described), this is ossified, and fills a large groove all along the ramus. 
The lower view (fig. 2) shows the superficial bones that form the hard palate ; the pre- 
maxillaries (see also tig. 4, pa.) form the narrow fore part of a long ellipse, truncated 
behind. The dentary region is shorter and thicker than the palatine process. The 
two palatine processes together form a long lanceolate, leafy structure, with their flat, 
high suture, simulating a mid-rib. I could find no separate front paired vomers ; as in 
the Mole and Shrew, these are probably connate with the premaxillary. 
The short jugal process of the maxillary projects beyond the last large tooth-pulp ; 
of these I find five large pulps in each maxillary, and three small ones in the pre- 
maxillary. 
Inside the crenate alveolar wall the palatine plate of the maxillary is divided by a 
groove into two subequal narrow tracts. Each of these ends in front in a sharp spike, 
the outer binding on the inside of the alveolar plate of the premaxillary; and the inner 
on its palatine process ; thus the anterior palatine foramina are very long slits. 
2F % 
