25 



but the same thin laminate bone. Has only a slight 

 articulation with the meso-pterygoid in front instead of 

 the extensive one of the other side. 



Meso-pterygoid. — Not attac^ied to the dorsal edge of 

 the pterygoid but to its inner face. It hence occupies a 

 different plane to that of the meta-pterygoid. It is further 

 much smaller on this side. 



Pterygoid. — This is of a different shape on this side. 

 The forward thin rod is here thick and in fact stouter 

 than the remainder of the bone, which is reduced and 

 apparently merged into the forward portion. The left 

 pterygoid is both larger and stouter than the right — thus 

 differing from the left palatine, as will be seen below. 



Palatine. — Greatly modified on this side. Its anterior 

 extremity articulates directly with the upper end of t'he 

 maxilla instead of by the intervention of a short ligament. 

 In one specimen there was also a short ligament contain- 

 ing a sesamoid connecting the same extremity with the 

 anterior forward process of the pre-frontal. Behind the 

 anterior end there is a strong dorsal articulation with the 

 pre-frontal which is not found on the other side. The 

 ligamentous connection with the vomer also exists on this 

 side, but is apparently with the vomer only. The articu- 

 lation with the pterygoid is also different, the posterior 

 extremity of the palatine being forked and the pterygoid 

 fitting into the split thus formed, the interstices being 

 filled with cartilage. The left palatine is much shorter 

 than the right, but is more robust (cp. the pterygoid). 



3. — The Jaw Apparatus (Fig. b). 

 Ocular Side. 



Articular (-I^-)- — ^^^ ^ saddle-shaped articular sur- 

 face for the quadrate, behind which it sends up a promi- 



