Plate LXXIV Continued. 



PAGE. 



Fig. 6. STENOPOBA ANGULABIS Ulr 439 



6. Tangential section, x!8. showing the thin walls aul large acanthopores. 



G a. Vertical section, x!8, of a layer thicker than usual, showing thin walls 

 and absence of diaphragms. 



6 b. Another portion of same vertical section, x!8, showing two layers of 



zooecia. 



Keokuk group, Lagrange, Mo. 



Illinois State Museum. 



Fjg. 7. STENOPOBA CESTRIENSIS Ulr 442 



7. Tangential section, x35, showing the comparatively large cavity of the 



Acanthopores. 



7 a. Vertical section, x!8. 



Chester group, Chester III. 

 Illinois State Museum. 



