EXPLANATION OF PLATE LIX. 



Figs. 1-6. SPIRIFER MORTONANUS Miller p. 366 



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

 specimen. (W. M., No. 13328.) 4-6. Pedicle, posterior and 

 anterior views of a nearly complete specimen. (W. M., No. 

 13321.) 



Crawfordsville beds, Crawfordsville, Indiana. 



Figs. 7-14. BRACHYTHYRIS ALTONENSIS n. sp p. 379 



7-10. Pedicle, brachial, anterior and posterior views of a very per- 

 fect internal cast. 11-14. Pedicle, brachial, lateral and an- 

 terior views of another specimen. Cotypes. (W. M., No. 

 10925.) 



St. Louis limestone, i mile above Alton, Illinois. 



Figs. 15-19. BRACHYTHYRIS SEMIPLICATA (Hall) p. 380 



Pedicle, brachial, anterior, lateral and posterior views of a nearly 

 perfect specimen. (W. M., No. 14776.) 



Kinderhook, 3^/2 miles N. W. of Joncsboro, Illinois. 



134 



