308 



FOSSIL REPTILES. 



seven in the monitors. The crocodiles have an infinite num- 

 ber of them, small and irregular. A dolphin would have but 

 two or three towards the end. 



There is a coronoid apophysis, raised, obtuse, whose ante- 

 rior edge is widened as in the monitors. No crocodile has 

 anything of the kind. That of the dolphin is much smaller 

 and farther back. In the iguana it is more pointed. 



The articulary facet is concave, and very near the posterior 

 end of the jaw, as in all the Saurians, but it is lower than the 

 dentary edge, as in the monitors. In the crocodiles and the 

 iguanas it is higher, or, at least, upon a level. The dolphins 

 have it convex, and placed altogether at the end. 



The apophysis for the muscle, which is analogous to the 

 digastric, is short, as in the iguana. The crocodile has it 

 longer, and the monitor still more so. In fine, the composi- 

 tion of this jaw shows greater relations with the monitor, than 

 with any other existing saurian, and entirely excludes the 

 cetacea ; these last having, like all the mammifera, each side 

 of the lower jaw of one piece. 



With respect to the further composition of this jaw, there 

 is no great oval foramen at its external face 5 the coronoid 

 apophysis is a bone apart, analogous to that which, after 

 M. Cuvier, we have called supplementary. The articulary 

 bone makes by itself the hinder apophysis, and pushes out 

 the angular bone very forward. The sub-angular is united 

 squarely with the dentary, and there is a small opening in the 

 opercular. 



In all these respects, the animal of which we speak ap- 

 proaches most to the monitor. It approaches it even more 

 than it does the iguana, as well in the lower jaw, as in the 

 structure of the teeth, their figure, and insertion. Though, in 

 this respect, there is something particular. 



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

 the internal face of the two jaws, without the maxillary bones 

 being raised to envelope them in their alveoli. But here the 



