PLATE XXIII. 



Page. 

 BELLEROPHON MAJUSCULUS 256 



Fig. 1. View of aperture, callus, and body-whorl. Natural size. 



1 a. Lateral view of fig. 1. 



ORTHOCERAS EUREKENSIS 265 



Fig. 2. Lateral view, showing curvature of the chambered portion of the tnbe. Natural 

 size. 



2 a. One of the septa, with the small siphuncle and areole about it. 



HYOLITHES CARBOXARIA , 264 



Fig. 3. Enlargement to three diameters of the type specimen. 



CONULARIA MlSSOURIENSIS 264 



Fig. 4. A crushed specimen. Natural size. 



MACRODON HAMILTON^ 243 



Fig. 5. Cast of right valve. Natural size. 

 5 a, &. Casts of left valve. Natural size. 



be. Enlargement of the surface of another specimen, to show the characteristic 

 radiating and concentric lines. 



EDMONDIA MEDON 245 



Fig. 6. Right and left valve. Natural size. 



SANGUINOLITES STRIATUS 249 



Fig. 7. Left valve. Natural size. 



