Plate LXXUI Continued. 



6 b. Peripheral portion of a zooe3ia wall of a vertical section. x50. This sec- 

 tion was prepared from the same specimen that furnished fig. (i a. It 

 shows the supposed communication pores, the laminated structure of 

 the walls, and the thick margin of the opening in the diaphragms. 



6 c. Vertical section, xis, showing arrangement of diaphragms in the com- 

 paratively narrow "mature" region. 

 Chester group, Sloan's Valley, Ky. 

 E. O. Ulrich's collection. 



Fig. 7. STBNOPORA MEEKANA Ulr I4S 



7. Vertical section, x!8. 



I a. Tangential section, x!8. 



Chester group, Chester, 111, 

 Illinois State Museum. 



Fig. 8. STENOPOKA CABBONABIA ( Worthen) 445 



8. Tangential section, x!8. 



8 a. Three tubes of one vertical section, and one wall of another, x!8, show- 

 ing structure of walls in the typical form of the species. 

 Upper Coal Measures, Caseyville, III. 

 Illinois State Museum. 



Fig. 9. STENOPOBA CABBONAKIA var. CONFEKTA Ulr 445 



9. Tangential section, x!8, showing variations in wall structure, perforated 



diaphragms, and strong acanthopores. 



II a. Vertical section, x!8, showing the close arrangement of the wall swell- 



ings. 



Upper Coal Measures, Caseyville, III. 



Illinois State Museum. 



Fig. 10. STENOPOBA CABBONABIA var. MACULOS A Ulr ... 145 



10. Tangential section, x!8, showing one of the macula-, and the large 



zooecia about it. 



10 a. Peripheral portion of a vertical section, x!8. Same locality and collec- 

 tion as preceding. 



