50 The Geology of Cambridgeshire 



but on the whole fresh-water conditions have always prevailed 

 south of Littleport. 



The fresh-water fauna recorded is meagre and includes 

 only species now common in the district. The marine fauna 

 is notable for its abundant foraminifera which are often 

 numerous enough to render certain beds quite sandy. Bones 

 of the seal, whale, and grampus are occasionally met with. 

 Scrobicularia piperata is the commonest and most charac- 

 teristic mollusc. 





