PLATE 68. 

 Orthonychia praeconicum sp. nov. 

 Page 254. 

 Figs. 1, 2* Lateral views of two specimens. 



Platyceras angulare Rowe 

 - Page 255. ■ 



Figs. 3, 4. View of the spire and the lateral aspect of a nearly complete specimen. 



Platyceras dumosum Conrad 

 Page 256. 



Fig. 5. Lateral view showing spine bases. 



Platyceras elongatum var. parvum. n. var. 

 Page 256. 



Fig. 6. Lateral view of a nearly complete example. 



Platyceras gebhardi Conrad 

 Page 256. 



Figs. 7, 8. Spiral views of two small individuals. 

 Figs. 9, 10. Lateral views of the same specimens. 



Platyceras cf. gracile Ohern 

 Page 257. 



Figs. 11-13. Lateral views of three individuals. 



Platyceras magnificnm Hall 

 Page 257. 



Figs. 14-15. Spiral views of two normal specimens. 



Fig. 16. Spiral view of a less ventricose specimen. 



Fig. 17. Spiral view of a specimen with the apex of the shell incomplete. 



