PLATE XLIV. 



Fbnestella dispanda. 



Vngell* 



Fig. 1. A fragment, showing tlie comparative size of tlio branches and dissepiments and manner of 

 growth, natural size. 



Fig. 2. An enlargoment of a i>orlion of tho non-<'i'lliiIiferous face of a frond. (X 6.) 



Fig. 3. An enlargement of a portion of tlie cclluliforoiis fare of a fnind, showing the fomi and arrange- 

 ment of the cell apertin-es. (X t5.) 



Fig. 4. An onlai-geinont of a jMirtion of the celluliferous face of another froml, showing a somewhat more 

 lax mode of gi-owth than the i)i-eceding specimen ; the cell apertures are more widely sepa- 

 rated, and the intenne<liate surface of the branch is tinely striated. (X <)•) 

 Upi>er Heldei'bcrg group. M'esterii New York. 



Fenestei-la sinuosa. 



Pago 116. 

 Fig. 5. The celluliferous face of a frond, natural size. 



Fig. (i. An enlargement of a portion of the same fi-ond. showing the form and arraiigement of the cell 

 apertures and the sinuous carinie. (X 6.) 



I'p|)er Helderberg group. Ntar CalecUmia, N. Y. 



Fe\e.stklla (Polypoka) distans. 



Page 161. 

 See Plate 37. 

 Fig. 7. A small fragment, showing the strong striated branches connected by slender dissepiments. (X 6.) 

 Upi>er Helderberg grouj). Near Buffalo, N. Y. 



Fenestella parai.lela. 



Page 107. 



Fig. 8. A portion of a frond, natural size, showing the appearance of the non-celluliferous face under 

 different degrees of weathei-ing. 



Fig. 9. A part of another well-preserved fr(md, natural size, showing angular branches and dissepiments. 



Fig. 10. A lateral view of a bianch without nodes. (X t!.) 



Fig. 11. A lateial view of a brunch, showing nodes perfectly preserved. (X 6.) 



Fig. 12. A portion of the non-celluliferous face of a frend, showing angular branches and slightly curved 

 difsepiments. (X 6.) 



Fig. 13. A portion of the celluliferous face of a froml, without nodes. The elevated margins of the aper- 

 tures being well pi-eserved it is not prol)able that this specimen was ornamented with noiles. 

 (XO.) 



Fig. 14. A portion of the celluliferous face of a fi-ond, showing distinct nodes on the cai-inse and oblique 

 cell apertui-es with prominent elevated margins. (X ti.) 



Fig. 15. A portion of the cellulifei-ous face of a fmnd showing nodiferous caiinte, more pi'ominent cell 

 ai>ertnrcs, and generally a moi-e robust apjiearance than either of the pi-eceding specimens. 

 (X6.) 



Fig. 11 G. A portion of the non-cellulifei-ous face of- a frond. This specimen has been so much weathered 

 that the carinse have disappeared, leaving a slight narrow channel along the middle of the 

 branches. (X '»•) 



Fig. 17. A Ri>ecimen whore the branches ami dia.<M;piments have been removed by solution. The illustra- 

 tion shows the filling of the fenestrules and cells. (X H.) 



Fig. 18. A jiortion of the non-cellulifemus face of a frond, weaihered so aa to show the fibrous structure 

 composing the more solid iM)rtion of the branches. (X •>.) 

 Upper Helderberg group. Near Buffalo, N. Y. 



