CHAPTEE III. 



The London Clay continued — Shells in London Waters — Mussels — 

 Pond and River Shells. 



Having made acquaintance with the various species 

 of moUusca to be met with in and about London 

 gardens, the collector, ever on the alert for something 

 new, will naturally turn his attention towards the 

 country ; but a visit en route to the different sheets 

 of water which ornament the metropolis will be 

 found to be not altogether unproductive in the way 

 of specimens. 



Chiefly conspicuous by their size are the large 

 swan mussels, Anodonta cygnea (PI. III., fig. 3), 

 adult specimens of which will measure Gin. by 3in.,* 

 and the pearl-bearing Unios of somewhat smaller 

 dimensions. Not that there are any pearls now to 



* A specimen of this mussel in the author's collection, 

 from the vicarage pond at Cowfold, Sussex, measures 7in. by 

 3|in. This is an unusually large one. But, some years 

 ago, several were taken out of a decoy pond in Firle Park, 

 Sussex, measuring 8 inches in length and 9 in circumference. 

 Cf. Merrifield, Nat. Hist, Brighton, p. 155 (1864). 



