FOSSIL GANOIDS 



157 



Eurynotus (Fig. 159) had attained a great depth of body 

 and prominent dorsal fin ; CJieirodus (Fig. 160) was dis- 

 tinctly flattened ; Semionotiis (Fig. 161) was small, with 



Fig. 160. — Cheirodus granulosus, Young. 

 (After Traquair.) 



X 



Coal Measures, Scotland. 



elaborate fin conditions ; AspidorJiynchus (Fig. 162) had a 

 remarkable pointed snout and a reduced number of body 



Fig. 161. — Semionotus kap 

 Keuper, Stuttgart. 



Fraas. 



(From ZlTTEL, after Fraas.) 



plates ; Microdon (Fig. 163), flattened like Cheirodus, had 



evolved an admirable series of crushing teeth (-Pycnodont). 



And, finally, is to be mentioned PalcBoniscns (Fig. 164), 



a form whose abundance, numerous species, and long sur- 



