PLATE 17 



Athyris faltonensis (Swallow) 

 Page 109. 



Figs. 1-3. Brachial, lateral and pedicle views of an immature specimen. 



(Snyder Creek shale of Callaway County.) 

 Fig. 4. Pedicle valve of an immature specimen. 



(Callaway limestone of Callaway County.) 



Athyns vittata (Hall) 

 Page 110. 



Figs. 8 and 9. Pedicle and lateral views of a small gibbous specimen. 



(Mineola limestone of Montgomery County.) 

 Figs. 10 and 15-16. Pedicle, brachial, and lateral views of a small specimen. 



(Mineola limestone of Montgomery County.) 



Hypothyris gregeri Branson 

 Page 91. 



Figs. 5-7. Brachial, lateral, and pedicle views of a small specimen. 



(Callaway limestone of Callaway County. X2.) 

 Figs. 11-14. Brachial, front, lateral, and pedicle views of a large specimen. 



(Callaway limestone of Callaway County. X2.) 



Pentamerella arata (Conrad) 

 Page 87. 



Fig. 17. Brachial valve of a broad, smooth specimen. 



Fig. 18. Pedicle valve of a small specimen with few large plications. 



Fig. 19. Mould of a pedicle valve of a large specimen with few plications. 



Fig. 20. Brachial view of a small specimen with indistinct plications. 



Fig. 21. Mould of pedicle valve with numerous sharp plications. 



Fig. 22. Pedicle view of specimen shown in fig. 20. 



Fig. 23. Side view of the specimen shown in figs. 20 and 22. 



(All specimens from the Mineola limestone of Montgomery County. X2.) 



