OSTREA. 



353 



Fios. 123-134. — Osliea diliiviana, L123, zone of Sehloenbachia roslrala, Devizes. Musouiii of Practical 

 Geology, No. 25820. Riffht valve. 124, 12."), Upper Greensaiul, Sidinoutli. Briti.sli Museum, L3326. 

 Left valve. 12(i 130, Clialk Marl, Folkestone. Se(l<;wick Museum. 12G, anterior view. 12S-130, 

 right valves. 127, anterior view of 128. 131-133, Base of Chalk Marl, HaslingfieU. Sedgwick 

 Museum. Right valves. 13t, Cenomanian Sandstone, Wilmington. Sedgwick Museum. Vertical 

 section of left valve. All x J-. 



