PLATE XXIIL 



PAGE. 



Fig. 1. AULOPORA ARACflNOIDEA 216 



1. A specimen in which the brauohing ia regiJar jind no dose leticulation is formed, gi-owng 



upon the stem of a ramose Chcetetes. Natural size. 

 Iff. The same. Enlarged. 

 16. Portion of a branch. Enlarged still further. 



Fig. 2. AcERVULARiA Clintonen.sis 227 



2. A few of the calices of a weathered specimen. Natural size. 

 2a. Transverse section of two corallites. Enlarged. 



Fig. 3. Favosites pleurodictyoides 231 



.3. Under side of a small specimen, in which part of the epitheca is preserved. Natural size. 

 3«. Under side of a decorticated .specimeo, from which the eiiitlieoa has been removed, show- 

 ing the mural pores on some of the best preserved corallites. Natural size. 

 36. Portion of the wall of a corallite, ahowing the mural poi-es. Enlarged. 



Fig. 4. Cystiphylluji Ohioense 234 



4. An adult specimen, viewed in profile. Natural size. 

 4a. Calice of the same. Natural size. 



Fig. 5. Zaphrentis Wortheni 235 



5. A specimen viewed laterally, so as to show the extreme obliquity of the calice. Natural 



size. 

 5a. The same, viewed from the front. Natural size. 



Fig. (). Zaphrentis Edwardsi 235 



6. Side view of a specimen. Natural size. 

 tia. Calice of the same. Greatly enlarged. 



Fig. 7. Favosites invaginata.... 232 



7. Corallum, of the natural size. For the sake of simplicity, the calices which cover the entire 



upper surface are omitted. 

 la. A few of the calices. Enlarged. 



