PLATE 40 D. 
Fig. 1. 558. 3. Fenestella elegans. (Pag. 164.) 
1 a. A portion of a frond, showing the non-celluliferons side. 
1 6. A portion enlarged, showing the form of fenestrule, striated surface of branches, etc. 
1 c. The impressions of the celluliferous side in the shale. 
1 d. A fragment showing the celluliferous side of the coral. 
1 e. The same enlarged, showing the form and arrangement of the cells. 
1 /. Another specimen of the celluliferous side. 
1 g. The same enlarged, showing the form and appearance of the cells where the surface is somewhat worn. 
Fig. 2. 559. 4. Fenestella tenuiceps. (Pag- 165.) 
2 a. The exterior surface of a large cyatliiform frond which has been crushed. 
2b. A portion of the last enlarged, showing the cells where the edges of the branches are worn. 
2 b t- A still farther enlargement of 2 b. 
2 c. An enlarged view, looking into the cells from a direction oblique to the surface of the frond.. 
2 d, e. Lateral and basal view of a fragment of the cup broken off just above the root. 
2 /. A specimen showing a fragment of the non-poriferous face of Polypora incepta and of Fenestella 
tenuiceps. 
2 g. A portion of the latter enlarged, showing the form of fenestrules and the granular worn surface. 
2 h. A portion of another fragment enlarged, showing the striated surface of the branches. 
560. 
A fragment natural size. 
5. Fenestella cribrosa. 
3 b. A portion of the same magnified. 
(Pag. 166.) 
561. 
6. Fenestella-. 
(Pag. 166.) 
Fig. 
5. 562. 1. Polypora incepta. (Pag. 167.) 
5 a. The inner surface of a part of a large frond. 
5 b. A portion of the same enlarged, showing the striated surface of the branches and the transverse bars. 
5 c. A cup-form specimen, showing the inner or non-celluliferous surface. 
5 d. The celluliferous face enlarged. 
5 e. The non-celluliferous face enlarged. 
5 /. Several branches from the celluliferous face greatly enlarged, showing the bifurcation of the branches, 
and the increasing rows of pores from the point of bifurcation upwards. 
