PLATE XV. 
Lichen alia torta. 
Page 31. 
Fig. 1. The external surface of the epitheca, showing- a folded and contorted condition of growth. 
Lower Pentamerus limestone. Schoharie, N. Y. 
Figs. 2, 3. The epithecal surface of two specimens, both of which are irregularly infolded and somewhat 
contorted. 
Lower Pentamerus limestone. Schoharie, N. Y. 
Fig. 4. The inner surface of the epitheca from which the 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 strife, 
and the radiating sharply elevated strise. 
Fig. 7. A portion of the celluliferous face of a specimen, showing the minute cell apertures 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 serialis. 
Page 32. 
See Plate 13. 
Fig. 6. An enlargement from the celluliferous face showing the cell apertures. 
Lower Helderberg group. Clarksville, N. Y. 
Lichenalia distans. 
Page 32. 
Fig. 8. A portion of the celluliferous face of a frond, natural size. The right hand portion of the figure 
represents 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 form and arrangement of the cell apertures. 
PALESCHARA ? DISSIMILIS. 
Page 35. 
Fig. 10. A portion of a large frond, natural size, showing the mode of growth, cell apertures, etc. 
Lower Helderberg group. Schoharie, N. Y. 
Fig. 11. An enlargement from the preceding, showing form of cell apertures. 
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 group. Clarksville, 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). 
