DESCRIPTION OF PLATES 329 



Plate 12 



Crania missouriensis n. sp page 292 



Figure 1. View of the type specimen. 

 Leptwna rhomboidalis (Wilck.) page 292 



Figure 2. Dorsal view of a nearly complete specimen. 



Figure 3. View of the interior of a ventral valve. 

 Orthothetes rubra n. sp page 29 1 



Figures 4-5. Ventral views of two nearly complete specimens. 

 Schizophoria siuallovi Hall page 29(5 



Figures 6-7. Posterior and veotral views of a nearly complete but 

 somewhat distorted specimen. 

 Rhipidomella michelinia L'Eveille page 295 



Figures 8-10. Views of three ventral valves. 

 Chonetes illinoisensis Worthen page 297 



Figure 11. View of a nearly complete ventral valve. 

 Chonetes logani N. & P page 299 



Figures 12-13. Views of two incomplete ventral valves. 

 Product us fernglenensis n. sp page 299 



Figures 14-15. Lateral and ventral views of a nearly perfect ventral 

 valve. 



Figures 16-17. Anterior views of two other ventral valves. 

 Prodnctus sampsoni n. sp page 300 



Figures 18-20. Ventral, dorsal, and lateral views of the type specimen 

 (from the Chouteau limestone, Pettis county, Mis- 

 souri ) . 



Figures 21-22. Views of two ventral valves from Fern Glen. 

 Retzia circularis S. A. M page 317 



Figure 23. Ventral view of a nearly perfect specimen. 

 Camarotoschia persintiata (Winchell) page 302 



Figure 24. Dorsal view of a somewhat crushed specimen. 



Figure 25. Anterior view of another distorted specimen (both from 

 collection of F. A. Sampson). 



XXVIII — Bull. Geol. Soc. Am., Vol. 20, 1908 



