PLATE XXVI 



PAGE 



Fig. 1. PiEURODicTYUM LENTICULARE (Hall) 218 



Portion of a corallum. Helderberg formation, New Scotland member, 

 near Cumberland. 



Figs. 2, 3. AULOPORA SCHOHARI.E Hall 219 



2. Branching corallum attached to a brachiopod. 



3. Several branches. X 3. 



Helderberg formation, Becraft member, Ernstville. 



Figs. 4, 5. AULOPORA SCHUCHERTI Swartz n. sp 219 



4. View of type. 



5. Enlargement of several branches. X 4. 



Helderberg formation, Keyser member, Cash Valley. 



Figs. 6, 7. CERATOPORA ? MARYLANDICA Swartz n. sp 220 



6. Slab covered with numerous branches. 



7. Transverse section of a single branch. X 5. 



Helderberg formation, Keyser member, Keyser, W. Va. 



Fig. 8. HALYSITES CATENULATUS Linne 220 



Corallum showing chain-like branching. Niagara formation, New 

 York. 



