ON MYLIOBATIS AND PTEROCEPHALA. I29 



Teeth extremely minute, either slightly projecting and serrated 

 or else ground flat so as to give a hexagonal outline. 



One species of this genus has been called the Devil-Fish, from 

 its repulsive appearance. From its very weak and small teeth it 

 seems not to possess such crushing power as Myliobatis, and it 

 probably subsists on softer food. 



Fig. I. — Ilyliohatis aquila. 



