FISHES. 



281 



system. They are Ceplialaspis, Coccosleus (fig. 191), Pteri- 

 chtliys (fig. 192), Polyphractus, and Pamphractus. The old 

 red sandstone of Scotland and England has yielded these 

 precious relics ; many specimens of which are now in tho 

 British and other Museums. 



FIG. 192. I'terichthys : Agass. 



6th Family. The PYCNODONTIDJ. Have broad or round 

 teeth embedded in the jaws. The genera range from the 

 triasic and oolitic to the tertiary period ; none now exist. 



7th Family. The CELACANTHID^E Have the bones of 

 the skeleton, especially those of the rays, in the form of 

 hollow tubes ; the tail fin is very peculiar ; the spinal column 

 is prolonged through the middle part thereof to form a long 

 style, and the rays are carried on a separate range of inter- 

 fipophysal bones ; their dentition resembles the preceding 

 family. The twelve genera which belong to it range between 

 the Devonian and cretaceous periods. 



