PALEONTOLOGY 



PLATE X. 



Inoceramus sublevis H. & M 393 



Fig. 1. View of the right side of a specimen retaining both valves, and most of the nacre- 

 ous layers of the shell. 



Fig. 2. View of the left side of an internal cast of both valves, showing the pustulose mark- 

 ings of the surface and near the postero-basal margin, what is evidently the 

 muscular impression. 



Fig. 3. Cardinal view of the same cast, showing the convexity of the valves. 



Inoceramus perplexus "Whitt 392 



Fig. 4. View of an imperfect left valve, showing the general form of the shell and the 



undulations of the surface. 

 Fig. 5. View of a very perfect right valve, retaining all the features of the nacreous shell. 



The profile, Fig. 3, Plate 8, is of this specimen. 



Endocostea sulcata Rcemer 404 



Fig. 6. View of the left side of an internal cast of both valves, showing the right valve 

 projecting above the left, and also the sulcus of the left valve. 



Vexiella humilis M. & H 414 



Fig. 7. View of ihe exterior of a right valve as obtained by a gutta-percha impression 



in the natural mold. 

 Fig. 8. View of a specimen retaining a part of the natural shell. 

 Fig. 9. View of a cast of the right valve, showing an elongate form. 

 Fig. 10. The 'left side of a specimen of the ordinary form. 

 Fig. 11. The right side of a more quadrate form. 



Fig. 12. Anterior profile of a cast showing the muscular impressions and marks of teeth. 

 Fig. 13. The interior of a left valve as obtained from a gutta-percha impression in the 



natural mold, showing the teeth, muscular impressions, and pallial line. 



Sph^eriola transversa Whitf 415 



Fig. 14. Anterior profile view of an imperfect individual retaining both valves, showing 



the convexity of the shell. 

 Fig. 15. Lateral view of the left side of the same specimen, with the beak of the right 



valve in outline. 

 Fig. 16. View of the interior of a left valve as obtained from a gutta-percha cast in the 



natural mold, showing the hinge and the muscular impressions. 



