334 



AMIOIDEI 



LiodesmuSy Wag. ; Jurassic, Bavaria ; Megalurus, Ag. ; Jurassic, 

 Europe ; Cretaceous, Brazil. Amiopsis, Kner ; Cretaceous, Europe. Amia t 

 L., living, North America ; Miocene and Eocene, Europe. 



FIG. 313. 



Dapedius politus, Leach ; Lower Jurassic, Dorsetshire. (After A. S. Woodward, 

 Vert. Palaeontology.) 



Family SEMIONOTIDAB. The trunk becomes deepened, especially in 

 Dapedius, where it is much compressed, and there is a corresponding 

 extension of the dorsal and anal fins. The mouth is small, and the teeth 

 differentiated into an outer pointed series on the jaws, and inner grinding 

 teeth, often very massive and rounded, on the splenial pterygoids and 



FIG. 314. 



Dapedius politus, Leach ; restored, with scales removed. (After A. S. Woodward, 

 Vert. Palaeontology.) 



vomers. The latter may fuse to a single bone (Lepidotus). In the more 

 specialised forms the grinding teeth form a pavement. The head is 

 completely covered by plates with ganoid ornament (Figs. 315, 316). A 



