'J'EKTTARY YEETEBEATA OF THE EAYCxM. 
for ll:(‘ jillaclinieiit of jioAvcrful muscles. Beneath the orbit the jugal bar is narrower 
IVom above downwards, but it is considerably tbicbened ventrally and bears several 
strong ridges. Posteriorly it turns upwards and widens out to some extent, meeting 
the zygomatic process of the squamosal in a long and nearly straight horizontal suture. 
'I'lie i)osterior angle of the jugal extends well back behind the anterior border of the 
glenoid surface, of which it may even help to form a part at the outer border. 
'file (7>Z.) tbim the greater part of the binder region of the palate, as 
well as of the side-walls of the nasal canal and of the mesopterygoid fossa. The 
nuion of their palatine plates with the maxilla is nearly transverse in front, and 
in or near the suture there is a pair of small posterior palatine foramina (PI. II. fig. 1, 
])]) f.), to which reference has been made above. 'Phe anterior end of the palatines is 
()])))osite the posterior column of m. "1 in the adult skull: behind this the maxillo- 
palatine suture runs backwards and slightly outwards. The posterior border of the 
palare is opposite the hinder end of m. o : it is greatly thickened and on either side 
of the median suture there are two roughened ridges directed forwards and outwards. 
Pehind the palate the ventral edges of the vertical plates of the bones are greatly 
thickened and dee])!)' notched externally, the notch forming the greater part of the 
posterior foramen (PI. 11. fig. 1, 'which has already been described in speaking of 
the maxilla. A little behind this the palatines join the pterygoids (PI. II. fig. l,pZ.), 
which form only a comparatively small portion of the descending plates which 
bound the mesopterygoid fossa. From tlie ventral edge of the plate the ])alato- 
pterygoid suture runs first forwaards and upwards, then directly upwards to the 
basis cranii, which is overlapped and embraced by the upper edges of both palatines 
and pterygoids. The palatines also form the side-’walls of the posterior portion of 
the nasal canal, and appear on the inner w’all of the orbits above the alveolar mass 
of the maxilla, rvith which they unite in suture behind, and from -which they are 
separated by the orbito-nasal foramen in front. The relations of these bones to one 
another and to the surrounding structures can be best understood by examining a 
skull of Dendrohyrax [Procavia] dorsalis, in which the sutures all remain open. 
The upper edge of the orbital plate of the palatine must have united with the orbito- 
sphenoid, hut the suture cannot be made out; indeed all the boundaries of the 
orbitos])henoid and alisphenoid are obscure, partly because these bones are very 
thin and greatly eracked. 
The 2 ^tcryyoids {pt.) form only the posterior part of the deep -vertical plates wdiich 
enclose the mesopterygoid fossa. The suture between them and the ])alatines in 
front has already been referred to. I'lieir ventral border is thickened and convex : 
])Osterioily they end in a slightly ])roniineut angle (see FI. 1.), above which the 
posterior border of the bone is very thin. The upj)er edge of the bone unites 
with the basis])henoid and runs high up on the side of that bone into the opening- 
lying between it and the glenoid surface of the squamosal, an opening doubtless 
