EXPLANATION OF PLATE XXXVIII. 



Figs. 1-5. SPIRIFER PIKENSIS Rowley p. 312 



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

 type. (R. R. R.) 



Burlington limestone, Louisiana, Missouri. 



Figs. 6-8. SPIRIFER SHEPARDI n. sp p. 313 



6-7. Views of two pedicle valves. 8. View of a brachial valve. 

 Cotypes. (W. M., No. 8540.) 



Pierson limestone, near Springfield, Missouri. 



Figs. 9-13. SPIRIFER LATIOR Swallow p. 316 



Lateral, pedicle, brachial, anterior and posterior views of a nearly 

 perfect specimen. (W. M., No. 6707.) 



Chouteau limestone, Chouteau Springs, Missouri. 



92 



