PLATE XII. 



Favosites Emmonsii. 



(See alHO Plates 9 and 11.) 

 Fig. 1. An enlargement of a longitudinal section, showing the transverse diaphragms, both entire 



and incomplete, and also the mural pores. Falls of the Ohio. 

 Fig. 2. An enlargement of a specimen showing more continuous diaphragms, which are coated 



with crystals of silex. Relerred with doubt to this species. Cayuga, Ontario 



county, N. Y. 

 Fig, 3. An enlargement of a wealhered surface of a .specimen, showing closely arranged diaphragms 



and single range of pores. From Livingston county, N. Y. 

 Fig. 4. An enlargement fi'om a poli.shed vertical section, having all the external characters of the 



species, showing the diaphragms mostly complete and the pores large and closely 



arranged. Probably a di.stinct species. Falls of the Ohio. 

 Fig. 5. An enlaigement of a polished vertical section of a variety having very small cells and 



partial diaphragms. Falls of the Ohio. 



Favosites epider.mata. 



(See aho PJutes C and 10.) 



Fig. 6. The lower side of a small, abruptly spreading variety, from Cayuga, Ontario. 



Fig. 9. Oblique view of the cell-apertures, enlarged Irom a specimen similar to fig. 6, showing the 

 characteristic stria; of the cell-walls and the projecting points representing the dia- 

 phragms. 



Fig. 10. Enlarged view of the upper surface, from the specimen fig. 6, showing complete dia- 

 phragms which are distinctly depressed at the angles. (This feature is not well 

 shown in the figure.) 



Fig. 11. An enlargement from a weathered decorticated surface of the under side of the specimen 

 fig. 6, showing the projecting points or remains of diaphragms, the faint strife and 

 the mural pores, the latter distinctly surrounded by an elevated border. 



Fig. 12. An enlargement from the weathered surface of the specimen fig. 5, plate G, showing the 

 closely arranged imperfect diaphragms. 



Fig. 13. An enlarged section of a polished surface of the same specimen (fig. 5, pi. 6), showing the 

 very numerous diaphragms which often ooalesje, and give a vesiculose structure to 

 the fossil. 



Favosites tuberosa ? 



Favosites lubnrosa Rominger 

 See Plates 4, 7, 8 and 11.) 



Fig. 7. An enlargement of a polished vertical section, showing both entire and incomplete dia- 

 phragms and strong cell-walls. The external character of the cells is entirely similar 

 to the following foi-m. 



Fig. 8. An enlargement from the upper surface of a specimen fig. 1, plate 4, showing the imper- 

 fect diaphragms giving a stellate appearance. 



