EXPLANATION OF PLATE XXXIII. 



Figs. 1-3. DIELASMA OSCEOLENSIS n. sp p. 260 



Pedicle, brachial and lateral views of the holotype. (W. M., 

 No. 7743.) 



Lower Burlington limestone, Osccola, Missouri. 



Figs. 4-5. DIELASMA FERNGLENENSIS Weller p. 259 



Pedicle and brachial views of the holotype. (W. M., No. 4688.) 

 Fern Glen formation, near Kimmswick, Missouri. 



Figs. 6-11. DIELASMA SUBSPATULATUM n. sp p. 270 



Pedicle, brachial and lateral views of two specimens. Cotypes. 

 (W. M., No. 14254.) 



Washington County, Arkansas. 



Figs. 12-17. DIELASMA FORMOSUM Hall p. 265 



12-14. Pedicle, brachial and lateral views of the holotype of D. 

 obovata H. & C. (W. M., No. 12238.) 

 Salem limestone (?) , Kentucky. 



15-17. Pedicle, brachial and lateral views of a very perfect speci- 

 men of typical form. (W. M., No. 449.) 

 Salem limestone, Spergcn Hill, Indiana. 



Figs. 18-20. DIELASMA ILLINOISENSIS n. sp p. 267 



Pedicle, brachial and lateral views of the holotype. (W. M., No. 

 14770.) 



Chester Group, Paint Creek formation, near Modoc, Ran- 

 dolph County, Illinois. 



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