PLATE XXVIII. 



LlMOPTEKA CLUVATA. 

 Page 250. 



Ki^'- 1 . A large lefl valve showing the anterior curvature of the beak and the alternation of the radii. 

 Fig. 2. An internal cast of a lefl valve showing the inter-pallia! area covered with small pustules which 

 were apparently the points of attachment for umhonal muscles. The specimen shows the pal- 

 lial line and muscular impression. 

 ::. The left valve of a large specimen, showing the wing and some traces of the radii. The post-basal 

 margin is not sufficiently extended in the figure 

 Hamilton group. Madison Co., A'. 1" 



LlMOPTEKA BIAOROPTERA. 

 Page US. 



See Plates 24. 26, 27. 29 and 92 

 i _ i. The right side of a laterally compressed specimen, represented on pi. 27. riir. 9, and pi. 29, fig. 2. 

 The ambonal scar is here shown in its true position. 

 5. The left side of an unusually elong men, due in pari to the breaking away of the margin 



of the left valve to the margin of the right valve. 

 Hamilton group. Madison Co., N. 1". 



