370 FOSSIL OSTEEID^ OF NORTH AMERICA. 



PLATE LII. 



EXOGYRA FORNICULATA White. (Pago 305. ) 



Figs. 1,2. — Exterior and interior views of tlio under valve; natural size. 



ExoGYKA LiEviuscuLA Roemer. (Page 305.) 



3, 4. — Two exterior views of tbe lower valve ; natural size. After Eoeiner. 

 5. — Lateral view of another lo« er valve. 



ExoGYRA wixcniCLLi White. (Page 307.) 



6,7. — Exterior and interior views of an upper valve; natural size. For views 

 of the lower valve see Plate LV. 



4 



