;ii>3 !»rin iJa:*(rii<t 



PLATE LIV— Contlnaai. 



Fenestklla (Loculipoka) CIKCUMSTATA. 



lisrii iiiifl SMirijn o« I Id B>i" Page 144. .,] yrf) ; ;. lii Instil 



Pigr. 23. An enlargement of the celluliferous face ; the cannae, having been broken away, showing the forai 

 and arrangement of the cell apertures. 



Fig. 23. An enlargement ; the lower portion of the figure I'epresents the non-celluliferous face ; the upper 

 right hand portion i-epresents a specimen with the non-cellulifei-ous face broken away, show- 

 ing the base of the reverae side. (X 6.) 



Fig. 24. An enlargement, showing reverae side, corresponding to the summits of the carinse and connect- 

 ing scalae of Hemitrj-pa ; the lower right hand comer represents this tissue broken away, show- 

 ing the celluliferous face of the frond. (X 6.) 



Fig. 25. An enlargement of the non-celluliferous face of a frond similar to the preceding. (X tJ.) 

 Upper Helderberg group. Walpole, Ontario, Canada. 



itead) Koj 



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