292 



Bole, smaller than the preceding ; and above that a void, in consequence 

 of the coronoidal not turning towards the inner surface : the anterior point 

 of this space is bordered by a small bone of a crescent form. The condyle, 

 all the superior surface of the posterior apophysis, and all the internal 

 surface of this part, belongs to the articular bone. In the crocodile there 

 is no sensible coronoidal apophysis. 



The lower jaw of the monitor is composed of the same number of 

 . bones as in the crocodile ; but, in the monitor, the angular is much 

 shorter and narrower, and the coronoidal terminates as if truncated, 

 where it unites with the dental ; the large oval hole not- being left be- 

 tween them, which is observed in the crocodile. The coronoid apo- 

 physis is formed by the bone which, in the crocodile* is termed the cres- 

 cent bone. The articular bone alone forms the posterior apophysis ; and 

 joins, with its internal surface, the crescent,, and carries to the upper edge 

 of the bone the opening for the entry of the maxillary nerve, which 

 opening is so large in the crocodile. In the monitor, also, there is no 

 opening in the inner surface between the opercular and the angular bone; 

 but there is a small one in the opercular itself, and a larger one between 

 that bone and the dental.: 



In the lower jaw of the animal of Maestricht, of which the coronoidal 

 apophysis, is seen, at s, the angular bone at t, and the dental at u and y, 

 there is no large oval hole in the external surface ; the coronoid process 

 is a distinct bone> analogous with the crescent-formed bone f the articular 

 bone alone forms the posterior apophysis, and disposes the angular much 

 forwarder ; the coronoidal unites with the dental bone in a straight trans- 

 verse suture ; and there exists a small opening in the opercular bone. 



This animal, therefore, approaches the nearest to the monitor, nearer 

 even than to the iguana, in the conformation of the lower jaw, as well 

 as in the structure, figure, and insertion of the teeth; although, in this 

 jatter respect, there exists a peculiarity in the fossil animal. 



In the monitor, as in the iguana, the teeth simply adhere to the in- 

 ternal surface of the two jaws, without the maxillary bone rising to 



