388 



FOSSIL OSTREID^ OF NORTH AMERICA. 



PLATE LXl. 

 OsTEEA GLABKA Meek & Haydeii. (Page 307.) 



Fig. 1. — Interior view of a lower valve from Wyoming. 



2, 3. — Upper and lateral views of a specimen from the state of Nuevo Leon, Mexico. 



OsTREA suBTRiGONALis Evaus & Shumard. (Page 308.) 



4. — Exterior view of an upper valve; natural size. 



5. — Interior view of the same example. 



6. — Exterior view of a lower valve. 



7. — Interior view of another lower valve. 



