

Plate XXXVI Continued. 



PAGE. 



Fig. 6. LBPTOTETPA HEXAGOXALTS Ulr ..................................................... 455 



' 6. An example attached to a small Orthoce.ras or Hyolithes. Natural 



size. 

 (i a. Surface of same x!2. 



Trenton limestone, Calhoun Co., 111. 



Illinois State Museum, and E. O. Ulrich's collection. 



Fig. 7. LEPTOTBTPA FILIOSA? (d'Orbigny) 



7. Tangential seclion. showing small and infrequent acanthopores, xlS. 

 7 a. Vertical sextion x!8. 



Trenton limestone, Calhoun Co., III. 

 Illinois State Museum. 







-' 





