PLATE XLVIII. 
Fenestella latijunotuka. 
Page 138. 
Fig. 1. An enlargement of a portion of the non-celluliferous face of a frond, showing very irregular 
branches, with frequent elevations around the lower portion of the fenestrules and numerous 
strong nodes. (X 6.) 
Fig. 2. A portion of the non-celluliferous face of a frond. The branches present a very irregular 
appearance, and many of the strong nodes are prolonged into spines. (X 6.) 
Fig. 3. A portion of the celluliferous face of a frond with the Carinas removed, showing the form and 
arrangement of the cell apertures. The branches are remarkably regular as compared with 
the opposite face. The lithographic figure fails to represent the original drawing. (X 6.) 
Fig. 4. A lateral view of a branch, showing a transverse section of the dissepiments, the cell apertures 
opening directly outward, and the strongly elevated carina, with its lateral denticulations. 
Fig. 5. A transverse section of the branches and carinse. 
Upper Helderberg group. Falls of the Ohio river. 
Fenestella bi-imbricata. 
Page 121. 
Fig-. 6. An enlargement of the non-celluliferous face of a frond, presenting a very irregular appearance, 
making it difficult to distinguish the branches and dissepiments. The surface of the frond 
also has been somewhat affected by maceration. (X 6.) 
Fig. 7. A portion of the non-celluliferous face of a frond, in which the branches and dissepiments cannot 
be distinguished from each other, the face of the frond presenting very much the appearance 
of some encrusting zoariuin. (X 6.) 
Fig. 8. An enlargement of a portion of the non-celluliferous face of a frond, showing the branches and 
dissepiments so thickened and involved as to have lost their distinctive character. (X 6.) 
Fig. 9. An enlargement from the celluliferous face of a frond. The branch at the left of the figure shows 
the expanded summit of the carina. The two adjacent branches show the interior ; the next 
branch shows the surface nearly worn through, and the two branches at the right preserve 
their normal condition. (X 6.) 
Fig. 10. An enlargement of the summits of the carinse on the celluliferous face. (X 6.) 
Fig. 11. A transverse section of the branches and carinse. (X 0.) 
Upper Helderberg group. Falls of the Ohio river. 
Fenestella interrupta. 
• Page 123. 
Fig. 12. An enlargement of a portion of the non-celluliferous face of a frond which has been worn and 
macerated. (X 6.) 
Fig. 13. A transverse section of the branches and carinse. (X 0.) 
Fig. 14. An enlargement of a portion of the non-celluliferous face of a frond, somewhat macerated. The 
branches and dissepiments are essentially undistinguishable from each other and are frequently 
disposed in a stellate manner. (X 6.) 
Fig. 15. An enlargement from the non-celluliferous face of a frond, showing angular and carinated 
branches and dissepiments of nearly equal width, which are so irregularly disposed that they 
cannot readily be distinguished from each other. (X 6.) 
Fig. 16. A portion of the non-celluliferous face of a frond, showing the branches and dissepiments of 
nearly equal width, but so irregularly disposed as not to be readily distinguished from each 
other. (X 6.) 
Fig. 17. An enlargement of a portion of the celluliferous face of a frond of this species. On the left of 
the figure the carinse are broken away, showing- the form and arrangement of the cell aper¬ 
tures. On the right of the figure the summits of the carinse are shown. (X 6.) (The litho¬ 
graphic figure has failed to give the proper effect.) 
Upper Helderberg group. Falls of the Ohio river. 
