EXPLANATION OF PLATE LXXIV. 



Figs. 1-11. RETICULARIA PSEUDOLINEATA (Hall) p. 429 



1-5. Pedicle, brachial, posterior, anterior and lateral views of the 

 holotype. (W. M., No. 7555.) 



Keokuk limestone, Warsaw, Illinois. 



6-8. Pedicle, brachial and lateral views of a nearly complete speci- 

 men. 9. View of a somewhat crushed pedicle valve. (W. M., 

 No. 13737.) 



Keokuk limestone, Keokuk, Iowa. 



10-11. Pedicle and brachial views of a nearly complete internal 

 cast. (D. K. G.. No. 2501.) 



Residual chert, South Branch, Callaway County, Missouri. 



Figs. 12-22. RETICULARIA SETIGERA (Hall) p. 431 



12-16. Pedicle, brachial, posterior, anterior and lateral views of 

 a very perfect specimen. (W. M., No. 7696.) 



Chester Group, Southern Illinois. 



17. View of the internal cast of a pedicle valve. 18. View of the 

 internal cast of a brachial valve. (W. M., No. 13972.) 



Seneca chert, Seneca, Missouri. 



19-22. Pedicle, brachial, lateral and posterior views of a nearly 

 complete specimen. (W. M., No. 7632.) 



Chester Group, Monroe County, Illinois. 



164 



