Journal of coNchologv. 39* 



THE LAND AND FRESHWATER MOLLUSCA OF 

 EAST NORFOLK. 



By the Ricv. S. SPENCER PEARCE, M.A., and 

 ARTHUR MAYFIELD. 



(Read before the Conchological Societ}-, No^■. i, 1893). 



The following list of the I>and and Freshwater Mollusca 

 of East Norfolk is the combined work of Mr. Arthur Mayfield, 

 now resident in Great Yarmouth, and of myself, who, during 

 the years 189 1-2, happened to be residing at Yelverton, a 

 village five miles south-east of Norwich city. Mr. Mayfield's 

 acquaintance with the molluscs of Norfolk has extended over 

 several years. At my suggestion, he kindly offered to co-operate 

 with me to work up the East Norfolk district as far as was 

 possible. For this purpose I made myself responsible for the 

 localities in the region lying to the south-east of the city, and 

 stretching towards Bungay and Yarmouth. Mr. Mayfield, on 

 his part, undertook the region on the other side of the city, 

 which may roughly be described as the valley of the Wensum 

 River, and localities on the west, north-west, and north-east of 

 Norwich. The list with regard to the vicinity of Norwich is 

 fairly complete. In many respects the district explored by us 

 is singular, and may conveniently and properly be considered 

 as falling into two areas, which in natural features are \er\ 

 distinct from one another. There is (i) //le hnv-Iying marsh 

 land which constitutes the wide valley of the River Yare with 

 its tributaries, the Wensum and the Taas; and that of the River 

 Bure with its many tributary streams. In these valleys, the 

 Bure and the Yare, which broaden out as the sea is approached 

 eastward, are situated most of the famous Norfolk lakes of 

 freshwater — the Broads. The number and the variety of the 

 freshwater molluscs in this low-lying area is immense ; and a 



