PLATE V. 



PAGE. 



Pii.EXOPORA (Ptilodictya) EXPANSA 114 



Fig. I. View of a portion of a frond, natnral size, showing a portion on tlie right, which presents the 

 outer surface, the larger part showing the inner face of the opposite lamina;. 



Eetepora angulata? Ill 



Fig. 2. View of a fragment of a frond, natural size. 



3. An enlargement of the striated surface. 



4. A still further enhirgeiiu-nt of a portion of the celluliferous face, showing the form and 



ariangemeut of tin- cell apertuies. 



Stictopoka magna 112 



Fig. .5. View of a fragment of a .sti])e which has been split through the center and presents the 

 inner face of the lamina?. Ifatural size. 

 6. An enlargement of a portion to show the arrangement of the lines of cells as presented on 

 the exposed surface. 



Clathropora Clintonensis 113 



Fig. 7. View of a frond, natural size, showing the large, irregularly formed perforations. Many of 

 the specimens observed have them still larger in propoif ion to the breadth of the branches 

 than in this one. 



Rhinopora frondosa 112 



Fig. 8. View of a fragment, natural size, showing the arrangement of the macul;e and grooves on 

 the surface. 

 9. An enlargement of one of the maculae, showing the clustering of larger pores. 



Strophomena patenta 115 



Fig. 10. View of the exterior of a ventral valve, as obtained from an impressi<m left on the suiface 

 of the stone, reversed by taking a cast in gutta-percha, giving the true foini of the shell 

 in the figure. 



Cypricardites ferrugineum ; 116 



Fig. 11. View of the left valve, as obtained by a gutta-percha impression in the rock. The valve has 

 been slightly injured by compression on the anterior end. 



Pleurotomaria inexpectans 117 



Fig. 12. View of one of the .specimens used in description, the surface-markings being iudicated 

 from another otherwise less perfect individual. 



Orthoceras Jamesi 118 



Fig. 13. View of tlie specihien described, enlarged to three diameters. 



Ill.tsxus Daytonensls 119 



Fig. 14. View of the glalirlla and fixed cbeeks of a specimen of the species. 



15. View of a small pytiidiiim associated with glabelhe of the form of the above. 



16. View of a larger pygidium of the .same form as flg. 15. 



