EXPLANATION OF PLATE VII. 



Figs. 1-4. ORTHOTETES KEOKUK Hall p. 75 



1-3. Pedicle, brachial and lateral views of a nearly complete but 

 exfoliated specimen. (W. M., No. 8652.) 



Keokuk limestone, Keokuk, Iowa. 



4. View of an incomplete internal cast of a pedicle valve showing 

 the median septum as a slit. (W. M., No. 363.) 

 Residual chert, Springfield, Missouri. 



FigS. 5-8. SCHELLWIENELLA CHOUTEAUENSIS n. Sp p. 64 



5-6. Pedicle and brachial views of a nearly complete specimen. 

 7-8. Brachial view of another less complete specimen. Cotypes. 

 (W. M., No. 9856.) 



Chouteau limestone, Pettis County, Missouri. 



FigS. 9-10. SCHUCHERTELLA Sp. 



Views of two imperfect pedicle valves. (W. M., No. 11353.) 

 Glen Park limestone, Glen Park, Missouri. 



IS 



