REPTILES ABUNDANT. 



75 



instance as a pigment, wherewith to delineate the belemnite 

 itself. 



FIG. 54. FIG. 55. 





Belemnoteuthis antiquus. 



Belemnite. 



FIG. 56. 



There are many fishes, some of which (acrodus, psammodus, 

 etc.) are presumed, from remains of their palatal bones, to have 

 been of the gigantic cartila- 

 ginous class (placoidean) now 

 represented by such as the 

 cestracion. It has been con- 

 sidered by Professor Owen as 

 worthy of notice, that, the 

 cestracion being an inhabitant 

 of the Australian seas, we 

 have, in both the botany and 

 ichthyology of this period, an 

 analogy to that continent. The 

 pycnodonts (thick-toothed) and 

 lepidoids (having thick scales) 

 are other families described 

 by M. Agassiz as extensively 



prevalent. 



Palatal teeth of Placodus gigas t 

 a Pycnodont Ganoid. 



