PLATE XV. 



LlOHENALlA TORTA. 

 Pago 31. 

 Fijf. 1 . The external surface of the epitheca, showinjf a folded and contorted condition of growth. 



Lower Pentamerus limestone, fichoharle, N. T. 

 Figs. 2, 3. The epithecal surface of two .sjiecimens, both of which ai-e irregularly infolded and somewbat 

 contoi-ted. 



Lower Pentamerus limestone. Schoharie, N. Y. 

 Fig. 4. The inner surface of the epitheca from which tho cellules have been removed by exfoliation. 



Lower Pentamerus limestone. Schoharie, N. Y. 

 Fig. 5. An enlargement of the preceding, showing the concentric undulations, the finer concentric stris, 



and the radiating shaiiily elevated strise. 

 Fig. 7. A j>ortion of the celluliferous face of a specimen, showing the minute cell apertui-es with irregular 

 low nodes which do not interrupt the continuity of the cells. A portion of the lower part is 

 denuded of the celluliferous crust, and presents the character of the surface shown in fig. 4. 

 Lower Pentamerus limestone. Schoharie, N. Y. 



LiCHENALIA SERIALI8. 

 Page 32. 

 See Plate 13. 

 Fig. 6. An enlargement from the celluliferous face showing the cell apertures. 

 Lower Helderberg group. ClarksviUe, N. Y. 



LlOHENALlA DISTAN8. 

 Page 32. 

 Fig. 8. A portion of the celluliferous face of a frond, natural size. The i-ight hand portion of the figui-e 

 repi"esents a broken and macerated fragment of a Dalmanites partially overgrown by a species 

 of Ceramopora. 



Lower Helderberg group. Schoharie, N. Y. 

 Fig. 9. An enlargement of the above, showing the fonn and arrangement of the cell apertures. 



PaLESCHAKA ? DI8SIMILI8. 

 Page 36. 

 Fig. 10. A portion of a large frond, natural size, showing the mode of g^rowth, cell apertures, etc 



Lower Helderberg gi-oup. Schoharie, N. Y. 

 Fig. 11. An enlargement from the preceding, showing form of cell !ii)ertures. 



Fig. 12. An enlargement from another specimen, showing a portion of the surface with the celluliferous part 

 denuded, and preserving long continuous channels with walls of the recumbent cell tubes. 

 Lower Helderberg g:i-oup. ClarksviUe, N. Y. 

 Fig. 13. An enlargement from the surface of the same specimen, showing a different form of cell apertures 

 from fig. 11 (possibly representing a distinct species). 



