EXPLANATION OF PLATE XXXII. 



Figs. 1-17. DIELASMA CHOUTEAUENSIS n. sp p. 257 



1-4. Pedicle, brachial, lateral and anterior views of a large specimen 

 figured by Hall and Clarke as D. formosa. (W. M., No. 12237.) 



Chouteau limestone, Missouri. 

 5. View of a pedicle valve. (W. M., No. 9703.) 



Chouteau limestone, Pettis County, Missouri. 



6-8. Pedicle, brachial and anterior views of a nearly perfect speci- 

 men. 9-12. Posterior, pedicle, brachial and lateral views of a 

 nearly perfect specimen. (W. M., No. 9666.) 



Chouteau limestone, Chouteau Springs, Missouri. 

 13-15. Pedicle, brachial and lateral views of an imperfect specimen. 

 16-17. Brachial and pedicle views of another imperfect speci- 

 men. (W. M., No. 8547.) 



Pierson limestone, near Springfield, Missouri. 



Figs. 18-28. DIELASMA INFLATA n. sp p. 264 



18-21. Lateral, brachial, pedicle and anterior views of a very perfect 

 specimen, the holotype. (W. M., No. 14235.) 



Salem limestone, Barrett's Station, Missouri. 



22-24. Lateral, brachial and pedicle views of a very perfect but nar- 

 rower specimen. (W. M., No. 7772.) 25-28. Lateral, anterior, 

 pedicle and brachial views of a specimen which probably be- 

 longs to this species. (W. M., No. 7773.) 

 Salem limestone, Spergen Hill, Indiana. 



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