PLATE XXI 



PAGE 



Figs. 1, 2. CYATHOPHYLLUM MARYLANDICUM Swartz n. sp 204 



1. Portion of a branch. Hyndman, Pennsylvania. 



2. View of calyx. Cash Valley, Lower Stromatopora bed. 



Helderberg formation, Keyser member. 



Figs. 3-6. HEUOPHYLLTJM CF. COKNICULTJM Lesueur 206 



3. 4. Side view and calyx. Martin Mountain, Allegany County. 



5, 6. Small individual, questionably referred to this species. Cumber- 

 land. 



Helderberg formation. 



Figs. 7-9. CYSTIPHYLLUM FASCICTJLATUM Swartz n. sp 207 



7. Side view of several corallites. 



8. Transverse section of same. 



9. Transverse section of a single corallite. 



Helderberg formation, Cumberland. 



Figs. 10, 11. COLUMNARIA ? HELDERBERG I.E Swartz n. sp 207 



10. Longitudinal section of type. 



11. Longitudinal section of same. X 5. 



Helderberg formation, Keyser member, Warrior Mountain, 

 Allegany County. 



12 



