FOSSIL GANOIDS 



157 



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

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

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



Fig. 160. Cheirodus granulosus, Young, x \. Coal Measures, Scotland. 

 (After TRAQUAIR.) 



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

 remarkable pointed snout and a reduced number of body 



Fig . 161 . Semionotus 

 Keuper, Stuttgart. 



, Fraas. X }. (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 Palaoniscus (Fig. 164), 



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



