LIST OF ILLUSTRATIONS 



PLATES 



I. Figs. 1-6. Cassidulus intermedins sp. nov. 

 Figs. 7-9. Cassidulus hemisphericus sp. nov. 



II. Hemiaster lacunosus sp. nov. 



III. Linthia variabilis sp. nov. 



IV. Columnar Sandstone of Lower Metarhinus Zone Ex- 



posed in the Canyon of White River. 



V. Upper figure. Green Clays Capped by Amynodon 

 Sandstone. 

 Lower figure. Fossil-bearing Sandstone, Upper Meta- 

 rhinus Zone. 



VI. Mesatirhinus superior sp. nov. 



VII. Metarhinus riparius sp. nov. 



VIII. Metarhinus earlei Osborn. 



IX. Figs. 1, 2. Dolichorhinus longiceps. 

 Fig. 3. Metarhinus cristatus sp. nov. 



X. Dolichorhinus fluminalis sp. nov. 



XL Fig. 1. Metarhinus earlei. 



Figs. 2, 3. Rhadinorhinus abbotti. 



XII. Sthenodectes incisivum Douglass. 



XIII. Isotelus iowensis Owen. 



XIV. Figs. 1-4. Bumastus beckeri sp. nov. 

 Fig. 5. Megalaspis beckeri sp. nov. 

 Figs. 6-8. Thaleops ovata Conrad. 



Figs. 9-15. Nileus vigilans Meek and Worthen. 



XV. Bigs. 1-4. Sphaerocoryphe maquoketensis sp. nov. 

 Figs. 5, 6. Amphilichas rhinoceros sp. nov. 

 Fig. 7. Amphilichas clermontensis sp. nov. 



XVI. Figs. 1-4. Cybeloides iowensis sp. nov. 



Figs. 5-7. Encrinurus pernodosus sp. nov. 

 Figs. 8, 9. Calymene fayettensis sp. nov. 



