PLATE XXXIV. 



Favosites Hamiltoni.1: n. sp. 



This species occurs abundantly in the calcareous beds o£ the Hamilton group in Western New 

 York, and especially on the shore of Lake Erie. It differs from the F. BilUngsi of Rominger in 

 its smaller cells, and other characters. Among the forms here embraced under the same desig- 

 nation, there are considerable differences, which are not regarded as of specific importance. 

 Fig. 1. The upper fractured surface, showing the open cells and continuous diaphragms. 

 Fig. 2. A lateral view of the preceding specimen, where the cells are partially free from stony 



matter, and preserving the continuous diaphragms. 

 Fig. 3. A fragment of a larger mass, showing a vertical section, with an oblique view of the cell- 

 openings upon the upper surface. The cell-walls are finely striate, but the pores are 

 indistinctly visible. 

 Fig. 4. A fragment of another specimen where the mural pores are well shown. 

 Fig. 5. A vertical section from a smaller hemispheric mass, from a polished surface. 

 Fig. 6. An enlargement of the columns with mural pores from the specimen fig. 3. 

 Fig. 7. An enlargement similar to the preceding from the specimen fig. 4. 

 Fig. 8. An enlargement of the cells from the upper side, showing the depressions of the diaphragms 



at the angles. 

 Fig. 9. An enlargement of the cells from the upper side of another specimen, showing some of the 

 diaphragms to be plain and flat, and others to be bent downward at the angles. 



Favosites placenta. 



(See Plate 35.) 

 Fig. 10. A section of a hemispheric form referred with doubt to F. placenta. The figure is enlarged 



to two diameters. 

 Fig. 11. An enlargement of a similar section from a small spheroidal form of the same species. 



The diaphragms are rarely continuous in either of the specimens. 



