PLATE 15 



Schisophoria striatula (Schlotheim) 

 Page 72. 



Fig. 1. Internal mould of a brachial valve of "an average specimen. 

 Fig. 3. Internal mould of an average pedicle valve. 



(Callaway limestone of Callaway County.) 

 Fig. 2. Brachial view of a large specimen. 

 Fig. 4. Pedicle view of a small specimen. 

 Figs. 5 and 6. Pedicle and side views of an average specimen. 



Fig. 7. Pedicle valve of a specimen with the front margin slightly more sinuate than 

 average. (Snyder Creek shale of Callaway County.) 



Schuchertella arctostriata (Hall) 

 Page 83. 



Figs. 8 and 12. Exteriors of pedicle and brachial valves. 

 (Snyder Creek shale of Callaway County.) 

 Fig. 9. Brachial valve of a specimen from the Lime Creek of Iowa. 



Productella callawaycnsis Swallow) 

 Page 85. 



Figs. 10 and 13. Pedicle and brachial views of a large specimen. 

 Fig. 11. Pedicle valve of a large specimen. 

 Fig. 1-1. Brachial view of a small specimen. 



(Snyder Creek shale of Callaway County.) 



