PLATE 28 



Pleurotomaria isaachii H. and W. 

 Page 117. 



Fig. 1. Side view of a large specimen. (Snyder Creek shale of Callaway County.) 

 Fig. 10. Side view of an average specimen with low spire (Snyder Creek shale of Cal- 

 laway County.) 

 Fig. 11. Top view of a slightly deformed specimen. (Snyder Creek shale of Callaway 

 County.) 



Pleurotomaria sp. undet. 

 Page 117. 



Fig. 2. An imperfect mould. (Mineola limestone of Ralls County.) 



Platyceras cf. erectum Hall 

 Page 122. 



Fig. 3. Side view of a large specimen. (Mineola limestone of Montgomery County.) 



Platyceras nodosum Conrad 

 Page 122. 



Fig. 4. Side view of an imperfect specimen. (Mineola limestone of Montgomery 



County.) 

 Fig. 5. Another view of the same specimen. 



Euomphalus cf. hecale Hall 

 Page 120. 



Fig. 6. Side view of an average specimen. (Snyder Creek shale of Callaway County.) 

 Fig. 7. Top view of the same specimen. 



Euryzone mineolaensis Branson 

 Page 118. 



Fig. 8. An imperfect specimen. (Mineola limestone of Ralls County.) 

 Fig. 9. A nearly complete specimen. (Mineola limestone of Ralls County.) 



