PLATE 12 



Stropheodonta cymbiformis Swallow 

 Page 76. 



Fig. 1. Brachial view of an average specimen. 



(Snyder Creek shale, Craghead Creek, Callaway County.) 

 Fig. 2. Pedicle view of the same specimen. 

 Fig. 3. Side view of the same specimen. 



Stropheodonta navalis Swallow 

 Page 82. 



Figs. 4 and 8. Pedicle and brachial views of an average specimen with both ends of 

 hinge broken away. (X%.) 



Figs. 5 and 7. Pedicle and brachial views of a small specimen with hinge of right side 

 nearly complete. 



Fig. 6. Back view of a large specimen. 



(All specimens from the Snyder Creek shale, Craghead Creek, Calla- 

 way County.) 



Stropheodonta equicostata Swallow 

 Page 79. 



Fig. 9. Pedicle view of a small specimen with average plications. 



Fig. 10. Pedicle view of a specimen with unusually short hinge and large plications. 



Figs. 11 and 14. Pedicle and lateral views of a small specimen. 



Figs. 12 and 15. Side views of average specimens taken from slightly different angles. 



Fig. 13. Pedicle view of an average specimen. 



Fig. 16. Pedicle view of an average specimen. 



Fig. 17. Brachial view of an average specimen. 



(All specimens from the Snyder Creek shale of Callaway County.) 



Stropheodonta mineolaensis Branson 

 Page 81. 



Figs. 18, 20, and 21. Side, pedicle, and brachial views of a convex specimen. 

 Fig. 19. Pedicle view of a flat specimen. (X^.) 



(All from the Mineola of Ralls County.) 



