PLATE XX. 



PALESCHARA. 



Paleschara inceustans, Hall. 



Fig. 1. A zoarium incrusting Streptelasma strictum, natural size. 



Fig. 2. An enlargement from the preceding, showing form and 



arrangement of the cells. x6. 



Lower Helderberg group. Near Clarksville, JV. Y. 



Paleschaea eadiata, Hall. 

 Fig. 3. An enlargement, showing the form and arrangement of the 

 cells. x6. 

 Lower Helderberg group. JVear Clarksville, 2^. Y, 



SAGENELLA. 



(Page 597.) 

 Sagenella elega:ns, Hall. 

 Fig. 4. An enlargement, showing the form of the cells. x6. 

 Niagara group. 



CERAMOPORA. 



(Page 563.) 



Ceeamopoea maculata. Hall. 



Figs. 5, 6, 7. The under side of three specimens, natural size. 

 Fig. 8. The upper surface of a specimen, natural size. 

 Fig. 9. An enlargement from the preceding figure, showing the form 

 and arrangement of the cell apertures. x6. 

 Niagara group. 



Ceeamopoea labeculoidea. Hall. 

 Fig. 10. An enlargement of a zoarium. x6. 



Lower Helderberg group. Hear Clarksville^ JV. Y. 



Ceeamopoea labecdla. Hall. 



Fig. 11. A fragment of a Fenestella, upon which are two separate 

 colonies of this species. x6. 

 Niagara group. 



Ceeamopoea paevicella. Hall. 



Fig. 12. A zoarium incrusting a Meeistella, natural size. 



Fig. 13. An enlargement from the surface of the preceding, showing 



the form and arrangement of the cell apertures. 



Lower Helderberg group. JVear Clarksville^ iVi Y. 



658 



