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MR. C. W. ANDREWS ON THE SKULL AND 
between the anterior and posterior quadrate facets. Of these, the antero-external (0.f.) 
is very large, oval in outline, and concave in all directions, but more deeply so from 
before backward; its outer edge forms a prominent lip on the lower edge of the 
squamosal prominence. The other facet (i,f.) is placed internal and posterior to the 
last; in form it is a very elongate oval, the long axis being antero-posterior, in which 
direction it is deeply concave: it looks outward and downward. The opening of a large 
pneumatic fossa separates it from the downwardly projecting process of the squamosal 
and also from the anterior facet. Mesiad of the posterior facet, but separated from it 
by a narrow flat ledge of bone, is a very deep pocket-like depression, into which open 
numerous foramina. The most posterior of these seems to be the fenestra ovalis; the 
others are probably pneumatic. Ventrally the tympanic cavity communicates by wide 
openings with the anterior tympanic recess and the eustachian canal. 
The squamosal region (Plate XIV., sg.) is deeply concave from before backward, 
and slightly convex from above downward. Posteriorly it forms the anterior face 
of the prominent lambdoidal crest; ventrally, as already mentioned, it is produced 
downward into a pointed process, which helps to form the outer boundary of the 
tympanic cavity. Anteriorly its ventral edge is formed by the prominent outer lip of 
the anterior quadrate facet (0.f.). About 7 mm, above this there is a prominent 
elongated tuberosity, the long axis of which is directed downward and inward; this I 
take to be the zygomatic process (zy.). From its upper end a slight ridge runs upward 
and backward to the lambdoidal crest (J.r.), and forms the lower boundary of the 
temporal fossa. Internal to the zygomatic process, and connected with it by a short 
ridge, is another angular projection, the pretympanic process; from this also a slight 
ridge runs upward and backward, but it soon dies away without reaching the 
main temporal ridge. 
As might be expected from the great massiveness of the mandible, the temporal 
fossee are very large and deep. ‘Their lower opening is bounded posteriorly by the 
zygomatic, anteriorly by the postorbital process (p.ord.p.), which approach to within 
17 mm. of each other, The fossee are much deeper than broad, and greatly constrict 
the side of the cranium. Superiorly they are bounded by the temporal ridges, which, 
as above mentioned, run upward and backward from the zygomatic process till they 
meet the lambdoidal crest (/.7.), with which they are confluent for 28mm. Leaving 
the lambdoidal ridge, they sweep forward, first towards the middle line, then outward, 
terminating anteriorly on the upper surface of the postorbital process, On the roof 
of the skull the fosse are separated one from another by an interval of about 
12 mm. only. 
On the side of the cranium, immediately below the constriction caused by the 
temporal fosse, and about on the same level as the quadrate facet, there is a deep 
infundibuliform depression, at the bottom of which the trigeminal foramen opens. 
This depression is marked off from the orbit by a ridge which runs upward and 
