the Coelacanth Fish. 333 



The pvearticulav of Man'opoma corresponds exactly to that 

 bone in Megalichthys ; in both they form the greater part of 

 tlie inner surface of the jaw and in both they meet at the 

 symphysis. 



The dentary of Coelacanths is undoubtedly correctly 

 determined. 



The three little tooth-bearing bones which rest on the 

 upper and linoual surfaces of the anterior ends of the pre- 

 articular and dentary are interpreted by Stensio as precoro- 

 iioids. This view cannot be accepted; their relation to the 

 bones on which they rest are quite different to those held by 

 tiie precoronoids in Osteolepids and Tetrapods, and they are 

 much furtlier forward than those bones ever are. 



They can, it seems to me, be most useluUy interpreted as 

 new formatiOiiSj formed by the fusion of teeth. The}^ agree 

 with the little tooth-bearing plates which occur on the copula 

 in Macropoma and on the branchial arches in other Coela- 

 canths, which are certainly neoinorphs. 



The coronoid of Coelacanths is certainly that bone, and 

 the angular, although incapable of certain determination, is 

 one of the three posterior infradentaries. 



Palate. — The pterygoid of Coelncanthus is extremely similar 

 in its relation to the pterygoid of Osteolepids and Labyriutho- 

 dontia, and is determined with certainty. 



The metapterygoid, certainly an ossification on the palato- 

 qnadrate cartilage, is analogous and probably homologous 

 with the metapterygoid. It agrees closely with one of the 

 continuous series of ossification which occuis in the cartilage 

 ill Osteolepids and rather strikingly with the epipterygoid of 

 an Embolomeious Labyrinthodont which I am describing 

 shoitly. 



There can be no doubt that the bay in its upper edge trans- 

 mitted the maxillary and mandibular divisions of the fifth 

 nerve, and that the o[)hthalmicus profundus passed out in 

 front of it. 



These relations, considered in connection with the absence 

 of any direct contact with the sphenoid, show that the 

 so-called basipter}goid is not necessarily that process. 



The palatine is considered by Stensio as an autopalatine — 

 a substitution-bone ; this view is founded presumably on the 

 fact that it does not support teeth directly. In Macropoma, 

 however, it has not the appearance of a cartilage-bone, and 

 the fact that the teeth are attached to a separate element does 

 not provide conclusive evidence, because this bone is identical 

 in type with the tooth-bearing bones of the front of the lower 



