Plate X. 



EXAMPLES OF STATE QUARRY SYNTHETODONT DEN- 

 TAL PLATES. 



All figures reduced slightly less than natural size. 



The larger specimens in the middle row and at the bottom of 

 the Plate are determinable as belonging to Syntlietodus calvini, 

 the remainder as imperfect examples of 8. trisulcatus ; all from 

 the State Quarry beds near North Liberty, in Johnson county, 

 Iowa. 



Originals preserved in the Museum of Iowa State University. 

 Pages 231 and 233 



332 



