PLATE XLVII— Continued. 



Fknestki.la STELLATA. 



Page 109. 



See Plate 45. 



Fig. 20. An enlai'gement of the non-celluUferous fa<re of a frond, having' branches quite rapidly and 

 bi*oadly widening to the bifui'cation.s, and with strong, oblique spinifovm nodes. (X 6.) 



Fig. 21. An enlargement fi-om near the base of a specimen, with the branches very much thickened. (X 6.) 



Fig. 22. An enlargement from the same specimen as fig. 20, but at a greater distance from the base, show- 

 ing strongly striated, nodose branches. (X 6.) 



Fig. 23. An enlargement, showing branches very gradually increasing in width, frequently of essentially 

 the same size for their entii-e length, and i-egulai-ly oval fenestrules which are slightly wider 

 than the branches. (X 6.) 



Fig. 24. An enlargement of a portion of the celluliferous face of a frond, showing numerous vei-y large 

 cell apertures, usually occurring neai- a di.ssepiment. (X 6.) 



Fig. 25. An enlargement of an oblique view of a portion of the celluliferous face of a specimen, to show 

 Ihe appearance and height of the elevations along the middle of the branch. (X <>•) 



Fig. 26. A lateral view of a branch enlarged, showing the nodes, and narrow dissepiments at right 

 angles to the axis of the branch. (X 6.) 



Rg. 27. A lateral view of a branch enlarged, to show the strongly elevated nodes on the celluliferous face, 

 the oblique nodes on the non-celluliferous face, and the oblique dissepiments. (X 6.) 



Fig. 28. A lateral view of a branch, showing i-egular nodes and dissepiments of a greater height than 

 those of the two i>receding specimens. 



Fig. 29. .\n enlargement of a portion of the celluliferous face of a frond, showing the form and arrange- 

 ment of the cell apertui-es, and the nodose elevation along the middle of the branch. 



Fig. ;}0. An enlargement of a portion of the celluliferous face of a frond, showing the cell apertures filled 

 with mineral matter, and a channel along the middle of the branches and sometimes along 

 the dissepiments. This is the most frequent condition of this species. (X 6.) 



Fig. 31. An enlargement of the top of a node or elevation ; a is the end of a nan-ow node. (X It!) 



Fig. 31a. The stellate summit of a node like tig. 32b. 



Fig. 31b. An enlargement, giving a lateral view of the upper part of a simple node. (X Hi.) 



Fig. 82. a. An enlargement of the top of an elevation, and 6. the side of the same elevation or node, all 

 gradations of elevations or nodes between fig. 316. and 326. occur. (X 16.) 



Fig. 32a. The summit of a more simple form of node than 32b. 



Fig. 321). An enlargement, giving lateral view of a more elevated form of node with plicated upper mar- 

 gins and stelliform summit. (X 16.) 



Fig. 33. A fragment of a frond, natural size, showing the comparative size of the branches and the mode 

 of growth. 



Fig. 34. A fragment, natural size. 



Fig. 35. An enlargfement of the non-celluliferous face of a frond. (X 6.) 



Fig. 36. An enlargement of the celluliferons face of a frond. (X 6). Figures 34, 35 and 36 are doubtfully 

 referred to this species. 



Upjter Helderberg group. FalU of the Ohio river. 



