114 PALAEONTOLOGY 



as seen from behind in the Myliobates aquila, is given in fig. 

 38. Both jaws are covered with a pavement of broad teeth, 



Fig. 38. 

 Jaws and teeth of an Eagle-Ray {Myliobates aquila). 



having a fiat grinding surface. To the genus Myliobates, as 

 now restricted, certain fossils from the London clay of Sheppy 

 (Myliobates toliapicus, Ag., fig. 39) belong. 



In Zygobates (fig. 40), the middle series of teeth is less 



Fig. 39. Pig. 40. 



Myliobates toliapicm Xuf/ohatcs Woodwardi 



Eocene, Sheppy). (Miocene). 



broad ; and a narrower series is interposed between the mid- 

 dle and the small lateral teeth. Existing rays showing this 

 modification are found in Brazilian seas ; fossil teeth of this 

 genus, c. <j., Zyyobates Woodwardi, Ag. (fig. to), occur in the 



