OF HARTING. 31 1 



able, it requires the destruction of a hundred and 

 thirty shells to find that one gem." " Mr. Unger, of 

 Edinburgh, is the chief dealer in these pearls, the best 

 kinds range from five pounds to fifty pounds each." 



The Common Swan Mussel (Anodon Cygnens) is 

 abundant in all our ponds, in the mud of which we 

 find it deeply sunk, with the posterior end only of the 

 shell, where the respiratory syphon is situated, above 

 the surface. Like the Pearl-bearing Mussels, this 

 species produces eggs which it retains within its shell 

 until they are hatched, but the young are at first so 

 unlike the mature individual, that, as they have been 

 frequently found adhering to the bodies of fishes, they 

 have been erroneously regarded as parasites. The 

 largest specimen we have met with in the Great Pond 

 at West Harting, measures six inches in length by 

 three in width ; it is of a yellowish green colour, which 

 deepens into a dark brown towards the posterior end. 

 We have also seen others in the same water much 

 smaller and much thinner than this, of a somewhat 

 different outline and with a beautiful glossy grass- 

 green epidermis, crossed by a few delicate striae of the 

 same colour, but whether these are a variety or young 

 individuals of the same species, we do not know. 

 " Ploughing the deep," in a literal sense, is one of the 

 occupations of this animal, and the large foot with 

 which it performs this operation is admirably developed 

 for the purpose, its numerous furrows in the mud are 

 distinctly visible. The smaller Bivalves inhabiting 

 the Great Pond and the streams issuing from it, are 

 the Cyclas cornea and Cyclas lacustris, the latter in 

 great abundance, and associated with them is the 

 Pisidium amnicum, which is also widely distributed 

 along the water courses traversing the Down Park and 

 the Nyewood meadows. Pisidium c-ineremn is another 

 species inhabiting the streams in the East Harting 

 district, and Pisidium obtusale is tolerably plentiful 

 in a shallow water-course in a meadow known as 



