i 



i 

 PLATE XVII. 



(Figures 1-15, 18-29, 33-46 by B. P. Whitfield; 16, 31, 3.! by F. B. Meek; 47-51 copies.) 



Legoiui. A. Cardinal area. j. Cardinal process. I 



D. Deltidiiun, pedicle-valve. v. Brachial ridges. 



C. Deltidium, brachial valve. a. Anterior adductors, 



t. Teeth. a'. Posterior adductor.s. 



b. Dental sockets. r. Diductors. 



Genus PRODUCTELLA, Hall. j 



Page 328. 



Pkoductella subaculeata, (Murchibou) Hall. 



Fig. 1. The exterior of a pedicle-valve. 



Corniferous limestone. Falls of the Ohio. 

 Fig. 2. The interior of a brachial valve ; showing the cardinal process. •' 



Corniferous limestone. East Victor, iV. Y. 



Productella spinulicosta, Hall. 



Figs. 3, 5. Two views of a jiedicle- valve. 



Corniferous limestone. Louisville, Kentucky. 

 Fig. -4. The exterior of a pedicle-valve. 



Marcellus shales. Western New York. , 



Fig. 6. A pedicle-valve referred with doubt to this species. ' 



Yellow sandstones. Burlington, Iowa. \ 



Productella Shumardiana, Hall. i 



Fig. 7. A pedicle-valve with distinct spinferous costal. This figure is from one of the original specimens ] 



of the species. i 



Yellow sandstones. Burlington, loiva. 



Productella navicella, Hall. 



Figs. 8, 9. Views of the interior and exterior of the pe<licle-valve. , 



Hamilton group. Western Neio York. 



i 



Genus STROPHALOSIA, King. ' 



(See Plates XVu, XVI.) • | 



Page 314. 



Strophalosia truncata, Hall. 



(See Plate XVb, fi-s. 24-2ti.) 

 Fig. 10. The interior of a brachial valve ; showing the cardinal process. 

 Fig. 11. The exterior of a brachial valve ; showing the convex umbo corresponding to the truncation of the 



apex of the opposite valve. X 2. 

 Figs. 12, 13. Two views of a pedicle-valve ; showing the truncation of the beak. X 2. 



Marcellus shales. JVestern Ne^o York. 

 Fig. 14. An impre.ssion of the external surface of the brachial and part of the pedicle-valve ; showing the 1 



cardinal areas and minute deltidia. X 2. i 



Hamilton grouji. JVear Tally, N. Y. 

 Fig. 15. An enlargement of the cardinal process ; showing its sinipit'. uncoalesced lobes. X 6. j 



Marcellus shales. Western New York. \ 



Genus PRODUCTELLA, Hall. 



P,nge 328. 



Productella subalata, Hall. 



Fig. It). Exterior of the pedicle- valve ; from one of the original specimens. 

 Hamilton group. Rock Island, Illinois. 



I 



J 



