88 Palaeontographica Americana 88 



Figure Page 



1. Area caroh'nensts Wagner 42 



"Miocene of North Carolina; 56 mm."; after Dall. 



2. Area carolinensis Wagner; Miocene of North Carolina. 



3. Area eallicestosa Dall 43 



Miocene of North Carolina. 



4. Interior of the same. 



5. Area eallicestosa Dall; Miocene of North Carolina; exterior of a right valve showing 

 the smoother ribs behind the middle. 



6. Area arata Say 44 



After Say. 



7. Area arata ^ay \ "Interior of right valve. St. Mary's River"; after Glenn. 



8. Area arata Say; "Exterior of left valve. Same locality" ; after Glenn. 



9. Area improeera Conrad 44 



Miocene of South Carolina. 



10. Interior of the same. 



11. Area improeera Conrad; Miocene of North Carolina.. 



12. Interior of the same. 



13. Area improeera Conrad; Miocene of Magnolia, North Carolina. 



14. Area improeera Conrad; Miocene of Magnolia, North Carolina; a valve with a 

 shorter hinge. 



15. Area improeera Conrad; Miocene of MagnoHa, North Carolina; a valve with flat, 

 rather smooth ribs. 



16. Area improeera Conrad; Miocene of Magnolia, North Carolina; a valve with nodu- 

 lous anterior ribs and smooth central ribs. 



17. A rea buecula Conrad 45 



Miocene of Magnolia, North Carolina. 



18. Umbonal view of the same, figured to show the convexity of A. buecula. 



19. A rea plicatura Conrad 45 



Pliocene of the Croatan beds of North Carolina; form with short hinge and 

 arcuate base. 



20. Area plicatura ConraA; Pliocene of the Croatan beds of North Carolina; another 

 form which may be placed in plicatura. 



21. Area subsiiiuata Conrad 46 



After Conrad. 



22. Area subsinuata Conrad; Pliocene of the Croatan beds of North Carolina. 



