Rhyn. 



880 



Rhynchodus frangens, Newb. 



V(t( a 



Pal. Ohio, Vol. 1873, page 



311, plate 28, fig. 2, natural size, outside face of left? lower? 

 mandibular tooth of a huge fish, which, among a number of 

 specimens, is so perfectly preserved as to retain the thin shelly 

 outside'over part of its side; 2 «, the triturating surface of the 

 broad part of the edge of fig. 2; 3, the inside face of the for- 

 ward part of the crown of another specimen tooth. Microscopic 

 structure like that of Coo/iUodus^ Psammodus^ etc., a netted 

 tissue of tubes wearing so as to leave a rough grinding surface 

 during the animal's life ; so like Buckland's Ghimcera town- 



