EXPLANATION OF PLATE XXXVI. 



Figs. 1-5. SPIRIFERINA SALEMENSIS n. sp p. 296 



Pedicle, brachial, lateral, posterior and anterior views of the holo- 

 type. (W. M., No. 13948.) 



Salem limestone, Bloomington, Indiana. 



Figs 6-7. DELTHYRIS CLARKSVILLENSIS (Winchell) p. 301 



6. View of a pedicle valve. 7. Brachial view of a somewhat 

 crushed specimen. (W. M., No. 6699.) 



Louisiana limestone, Louisiana, Missouri. 



Fig. 8. DELTHYRIS SUBORBICULARIS Weller p. 303 



View of a pedicle valve, the holotype. (W. M., No. 11352.) 

 Glen Park limestone, Glen Park, Missouri. 



Figs. 9-14. DELTHYRIS MISSOURIENSIS Weller p. 302 



9. View of a pedicle valve. 10. View of a brachial valve. (W. 

 M., No. 14276.) 



Hamburg oolite, Calhoun County, Illinois. 



11-12. Views of two pedicle valves. 13-14. Views of two brachial 

 valves. Cotypes. (W. M., No. 11351.) 



Glen Park limestone, Glen Park. Missouri. 



Figs. 15-24. DELTHYRIS NOVAMEXICANA (Miller) p. 304 



15-16. Views of two imperfect pedicle valves. 17. Posterior view 

 of an incomplete specimen. Cotypes of S. magnicostata Weller. 

 (W. M., No. 4690.) 



Fern Glen formation, near Kimmswick, Missouri. 

 18-19. Pedicle and posterior views of an incomplete specimen. 

 20-21. Pedicle and brachial views of a smaller incomplete 

 specimen. 22-24. Pedicle, anterior and posterior views of a 

 third specimen. (D. K. G.) 



Lake Valley beds, Lake Valley, New Mexico. 



Figs. 25-34. SPIRIFERINA SOLIDIROSTRIS White p. 292 



25. View of a pedicle valve. 26-27. Views of two brachial valves. 

 28. Brachial view of a somewhat crushed specimen. Cotypes. 

 (U. M., No. 1372.) 



Kinderhook, Bed No. 7, Burlington, Iowa. 



29. View of the interior of a pedicle valve showing the median 

 septum. 30. View of a pedicle valve. 31-32. Pedicle and 

 posterior views of a pedicle valve. 33-34. Views of two im- 

 perfect brachial valves. (W. M., No. 13949.) 

 Kinderhook, Le Grand, Iowa. 



Figs. 35-40. SPIRIFERINA SUBTEXTA White p. 291 



35-39. Pedicle, brachial, anterior, posterior and lateral views of 

 the holotype. (U. M., No. 1701.) 



Burlington limestone, Burlington, Iowa. 

 40. View of a pedicle valve. (W. M., No. 13914.) 



Fern Glen formation, near Kimmswick, Missouri. 



87 



