FOSSIL MOLLUSC A. 



281 



Nacton, Bucklesham, Foxhall, Waldrlngfield, and 

 thereabouts, these stones are very abundant. In the 

 Ipswich museum there may be seen an almost perfect 

 fauna, recovered from this missing and fragmentary 

 British Miocene deposit. 



The Pliocene beds in England lie almost entirely 

 on the east coast. A deposit of this period has lately 

 been discovered in Cornwall, and there are also patches 

 in Aberdeenshire ; but the shells are too meagre and 

 fragmentary in these outlying localities to refer the 

 fossil-collecting student to them, especially when he 



Fig. 26Z,—Mactra. 



Fig. 269. — Trochus (Crag and 

 recent). 



has access to the wonderfully rich Pliocene formations 

 of Norfolk, Suffolk, and Essex, where everybody 

 knows them by the name of " crags." The crag beds 

 are richest near the coast, as at Walton-on-the-Naze, 

 Felixstowe, Orford, and Aldborough, although they 

 extend inland, and " crag " pits are very common in 

 the neighbourhood of Ipswich ; and about Norwich 

 we have the ''crag" (latest formed of the entire 



