Plate XII. 



EXAMPLES OF STATE QUARRY SYNTHETODONT DEN- 

 TAL PLATES. 



All figures reduced slightly less than the natural size. 



In this Plate is shown a representative assortment of dental 

 plates belonging to Synthetodus calvini. The originals of Figs. 

 7, 9, 12-15, are interpreted as constituting the lower, and the 

 remainder, with the exception of Fig. 16, as the upper pave- 

 ment dentition of this species. In Fig. 16 is seen a unique cal- 

 cified vertebral body, also from the State Quarry "fish-beds," 

 whose relations are considered problematical. 



Originals preserved in the Museum of Comparative Zoology 

 at Cambridge, Mass. Pages 147 and 233 



340 



