PALEONTOLOGY. 

 PLATE X. 



Page. 



Inoceiumi's SL'Bi-F.vis H. &. M 393 



Fig. 1. View of thtr rif^lit side of a specimen retaining both valves, and most of the nacre- 

 ous layers of the sht-ll. 

 Fi(i. 2. View of tlie left side of an iuleriial 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. 



IjIOCEKAMfS PERPLKXl'S Whitl 392 



Fig. -1. A'iew 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 prolilo. Fig. 3, Plate 8, is of this si)ecimen. 



ExDoco.sTKA SULCATA Rcpmcr 404 



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

 l)rojeeting above the left, and also the sulcus of the left valve. 



^'l:^■ll:I.LA iumilis M. &. II 414 



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

 in the natural mold. 

 r Fig. H. View of a si)ecinicn retaining a part of the natural shell. 



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

 Fig. 10. The left side of a specimen of the ordiuiiry form. 

 Fig. 11. The right sidt; of a more (piadrate form. 



Fig. 1'2. Anterior ])rotile 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. 



Sl'IIitlUOLA TKAXSVERSA Whitf 41.5 



Fig. 14. Anterior i»rofile 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. IC. View of the interior of a left valve as obtained from a gutta-percha cast iu the 



natural mold, showing the hinge and the muscular impressions. 



k 



