64 



DINOCERATA. 



Figure 10. — Colonoceras agresUs, Marsh. Eocene. 

 B'iGURE 1). — Ilyrachyus Bairdianwi, Marsh. Kocene. 



Figure 72. — Amynodon advenm, iiar&h. Eocene. 

 Figure 7^.. — Eporeodon socia/ts,'i,\iirsh. Miocene. 



