35 



are, as a rnle, found only in sheltered waters, in shallow 

 bays, and at the mouths of estuaries. There is great con- 

 stancy in the characters of the cockles from the various 

 parts of the Lancashire and Cheshire coasts, no well-marked 

 varieties being found. The difference in size observed in 

 specimens from various parts of this district are most 

 probably due to the extent to which the beds have been 

 fished or disturbed in late years. Generally the influence 

 of some fresh water* seems to be favourable in that cockles 

 are more abundant in the neighbourhood of the mouths of 

 rivers, but the largest specimens are found only in areas 

 far removed from the influence of fresh water. Large 

 cockles, with shells two inches in length, are found on 

 some parts of the North Coast of Devon, in Barra, in the 

 Western Hebrides, and in the Scilly Isles. In Barra 

 these large cockles are sufficiently numerous to form the 

 material for an important fishery. Such giant forms are 

 not found on the Lancashire coast, where the average 

 length is about one and a half inches. Here the market- 

 able cockle has a minimum breadth of f inch, the size being 

 fixed by the Sea-Fisheries Committee's Bye-law. With 

 the exercise of proper care on the part of fishermen to 

 take only well-grown animals, there can be no doubt that 

 the Lancashire and Cheshire cockle fisheries might be 

 more largely developed, since the physical conditions are 

 so suitable. 



The cockle inhabits the topmost layer of the sand, 

 burying itself to the depth of an inch at most. It lies in an 

 oblique position, and, when the bed is covered with water, 

 with the siphons projecting slightly above the surface 



* The influence of extreme salinity or freshness, as might be exjiected, is to 

 produce well-marked variations in the character of the shell. See Bateson, 

 rhil. Trans. Roy. Soc, vol. CLXXX. B., pp. 297—330, 1889; and Forbes 

 and Ilanley, History of the British Mollusca, 1850, vol. II., p. 21. 



