PLATE 19. 



Fig. 1. 429. 1. Rhinofora vekeucosa. ( Pag. 48.) 



1 a. Fragment of the natural size. 



1 6. A fragment of the natural size, showing a ramose elevated ridge running over the surface. 



1 c. A portion enlarged, showing the form and arrangement of the cells. 



Fig. 2. 430. 2. Rhinopora tubulosa. (Pag- 49.) 



2 a. A fragment of this species, of the natural size. 



2 6. A section of 2 a, showing the form, the interior being filled withehaly rsatter. 



2 c. A portion of the surface enlarged, showing the form and arrangement of the cellules. 



Fig. 3. 431. 4. Retepora angulata. (Pag. 49.) 



3 a. The poriferous face of a portion of a frond (the specimen preserved in shale). 



3 h. The non-poriferous face of another individual. 1 c. A portion of 3 a enlarged. 



Z d. K portion of the non-poriferous face of 3 6 enlarged. 



3 e, f, g, h. The poriferous face of two small fragments from calcareous strata, natural size and enlarged. 



In these the pores are very conspicuous, and the fenestrules differing in size and form in the two spe- 

 cimens. 



Fig. 4. 432. 1. Fenestella prisca? (Pag. 50.) 



4 a. The base of a frond, showing the external poriferous face. 4 6. A portion of the same enlarged. 

 4 c. The non-poriferous face of a portion of a frond. 



4 d. Several of the fenestrules near the base enlarged, showing distinctly the oval form. 



4 e. Several of the fenestrules enlarged (from a portion of the surface which lias been worn down), showing 



a quadrangular form. 

 4 /. A surface of stone, preserving the impression of the poriferous and non-poriferous faces of this coral. 

 4"§:. A portion enlarged, showing the thin sharp lines of impression of the branches of the poriferous face. 

 4 h. Enlargement of the spaces filling the fenestrules on the non-poriferous face. 



4 i, k, I, m. Similar enlarged portions of the impressions of the two faces of the coral. 



Fig. 5. 433. 2. Fenestella tenui?. (Pag. 51.) 



5 a. A portion of the frond of this species, natural size. 

 5 6. A portion of the poriferous face magnified. 



5 c. A portion of the non-poriferous face magnified, showing distinctly the form of the fenestrules. 



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