A MONOGRAPH 



OF THE 



CRAG MOLLUSCA, 



WITH 



DESCRIPTION OF SHELLS 



FROM THE 



UPPER TERTIARIES OF THE BRITISH ISLES. 



SEARLES V. WOOD, F.G.S. 



VOL. II. 



BIVALVES. 



LONDON: 



PRINTED FOR THE PAL)ONTOGRAPHICAL SOCIETY. 

 18511861. 



