PLATE XLVII. 

 Fenestella ldnulata. 



P&ne 121. 



Fig. 1 . An enlai'gement of a iiortion of the non-celluliferous face of a frond ; the dissepiments are broad, 

 curved and somewhat elevated aliove the bi-anches, giving to the surface a peculiar appear- 

 ance. The nodes upon the upper margins of the dissepiments are but moderately developed. 

 (X6.) 



Fig. 2. An enlargement of a portion of the noncelliilifei-ous face of a frond ; the branches and dissepi- 

 ments are flattened from maceration. (X 6.) 



Fig. 3. An enlargement of a portion of the non-celluliferous .side of a fTOn<l ; the dissepiments and their 

 noiies being so prominent as to in a measure obscure the branches. (X •>.) 



Fig. 4. An enlargement of a portion of the non-oellulifei-ous face of a frond ; the crescentiform elevations 

 on the dissepiments, and the moi-e slender no<ies on their upper margins. (X 6.) 



Fig. 5. An enlargement of the expanded summits of the cai-inie. (X ti.) 



Fig. 6. An enlargement of a portion of the cellulifei-ous face of a frond ; the carinae, having been i-emoved, 

 showing the foi-m and arrangement of the cell apertures. (X ^•) 



FigfS. 7, 8, 9. Transvei-se sections of bran(thes from ilifTcriMit specimens, showing considerable vai-iation in 

 the comparative height an<l width. 



Fig. 10. An enlargement of ii lateral view of a branch, showing transverse section of oblique dissepiments, 

 the height of the carina, ami the cell aj>ertui-e.s. (X 0.) 



Opj>er Helderberg group. Fallx of the Ohio river. 



FeNE-STELLA 8EKRATA. 



Page no. 



Fig. 11. An enlargement of a portion of the non-cclluliferous face of a frond, having comparatively large, 



quadrangular fenestrules, slender liis-sepiments, and string, spiniform nodes on the branches. 



(X6.) 

 Fig. 12. An enlargement of a pfrtion of the non-celluliferous face of another specimen, having smaller, 



more oval fenestrules, and comparatively much sti-onger branches, without nodes, though this 



may in a m('a,siire l>c due to maceration. 

 Fig. 13. An enlargement of a portion of the non-celluliferous .side of a frond, having subangidar fenestrules 



wider than the branches, the latter having numei-ous granules or .small nodes, which are much 



less conspicuous than those shown in tig 1 1 . 

 Fig. 14. An enlargement of a portion of the non-celluliferous face of a frond ; the fenestrules are narrower 



than in figs. 11 and 13, the nodes numei-ou.s and moi-e prominent than in fig. 13, though not as 



much so as in fig. 11. (X ti.) 

 Fig. 15. An enlargement of a portion of the celluliferous side of a fi-ond, showing angular branches and 



the cells o|)ening laterally, with the t)ran<-hes and disseiiiments sharply angular. (X 6.) 

 Fig. It). A lateral view of a branch enlarged, showing transverse .section of dissepiments, cell apertures 



and nodes. (X ')•) 

 Fig. 17. An obli<ine view of a portion of the celluliferous face of a frond ctilarf^-i'il, showing the serrated 



appearance of the summits of the branches. (X 6.) 

 Fig. 18. A transvei-se section of the branches. (X ti.) 

 Fig. 19. An enlargement of a portion of the non-celluliferous surface of a frond, referred with <loubt to 



this 8i)ecies. (X 6.) 



Upper Helderberg grouj). Falls of the Ohio river. 



