501 



Orac. 



lb '0. 



Oracanthus ? obliquus. St. John & Worthen, Geo. Sur. 



111., Vol 6, 

 1875, p. 477, 

 pi. 22, figs. 16 

 a to d ; uni- 

 que speci- 

 men. Upper 



StMln.m.^eolMM6. '^^ Keokuk. XL 

 Oracanthus rectus. St. John & Worthen, Geo. Sur 111., 



hraxcmthu^ rectus , SbJohri %Worthen. 



