PLATE XLII. 
Fenestella (Polypora) carinella. 
Page 153. 
Fig-. 1. An enlargement from the celluliferous face, showing the character and comparative size of 
the branches and dissepiments, the form and arrangement of the cell apertures, and the long¬ 
itudinal carinse separating the ranges of apertures. (X 0.) 
Fig. 2. An enlargement from the non-celluliferous face of the frond, showing the comparative size and 
character of the branches and dissepiments, and the form of the fenestrules. (X 6.) 
Upper Helderberg group. Near Buffalo, N. Y. 
Fenestela (Polypora) elongata. 
Page 153. 
Fig. 3. An enlargement from the non-celluliferous face of a frond, showing the comparative size and 
character of the branches and dissepiments and the form of the fenestrules. (X 6.) 
Fig. 4. An enlargement from the celluliferous face of a frond, showing the form and arrangement of 
the cell apertures, the continuous strise between the ranges of apertures, and the intermedi¬ 
ate interrupted strise. The surface of the branch at the right is broken away, showing the 
form and arrangement of the cells (X 6.) 
Upper Helderberg group. Onondaga Valley, N. Y. 
Fenestella (Polypora) celsipora. 
Page 150. 
See Plate 41. 
Fig. 5. The non-celluliferous face of a frond, natural size 
Fig. 6. An enlargement of a portion of fig. 5. The branches have from three to five striations, and are 
from two to four times the width of the dissepiments, and from two to three times the width of 
the fenestrules. (X 6.) 
Fig. 7. An enlargement of another portion of fig. 5. The branches are more slender than in the pre¬ 
ceding figure, the fenestrules are sub-quadrangular, and their width is equal to or greater 
than that of the branches. (X 6.) 
Fig. 8. An enlargement from the celluliferous face of a frond, showing the comparative size of the branches 
and dissepiments, the form and arrangement of the cell apertures, the carinse separating the 
ranges of apertures, when more than two ranges occur, and appearing as a central carina 
where only two ranges occur. (X 6.) 
Fig. 9. A fragment of the non-celluliferous face of a frond, natural size. 
Fig. 10. An enlargement of a portion of fig. 9, showing the comparative size and character of the branches 
and dissepiments, and the quadrangular form of the fenestrules. (X 6.) 
Upper Helderberg group. Walpole, Ontario, Canada. 
Fenestella verrucosa. 
Page 110. 
See Plate 46. 
Fig. 11. An enlargement from the non-celluliferous face of a frond, showing the comparative size and 
character of the branches and dissepiments, and the irregularly nodulose surface. (X 6.) 
Upper Helderberg group. Falls of the Ohio river. 
