OF MASSACHUSETTS. . 159 



Value of implements, ......... $15 



Value of shore property, $25 



Value of oysters on grant, $800 



Clam {My a arenaHa). 



Mya arenaria, commonly known as the " soft " or " long-neck " clam, 

 is found along the entire Massachusetts coast, wherever there is afforded 

 a sufficient shelter from the open ocean. Exposed beaches with open 

 surf are never inhabited by this mollusk, which is usually found on 

 the tide flats of bays, inlets and rivers, and on the sheltered beaches 

 between high and Ioav tide lines. The clam occurs in various kinds of 

 soil, from rocky gravel to soft mud, but grows best in a tenacious soil 

 of mud and sand, where it lies buried at a depth of from 6 to 12 inches. 



As Cape Cod marks the dividing line between a northern and a 

 southern fauna, it also divides the clam flats of Massachusetts. into two 

 distinct areas. The same clam is found both north and south of Cape 

 Cod, but the natural conditions under which it lives are quite different. 

 In comparing these two areas, several points of difference are noted. 



(1) The clam areas of the north coast are mostly large flats, while 

 those of the south shore are confined to a narrow shore strip, as Buz- 

 zards Bay and the south side of Cape Cod for certain geological reasons 

 do not possess flats, but merely beaches. 



(2) The rise and fall of the tide is much higher on the north shore, 

 thus giving an extent of available flats nearly six times the clam area 

 south of Cape Cod. 



(3) Clam growth as a rule is much faster on the north shore. This 

 is due to the great amount of tide flow over the river flats of the north 

 shore. Current is the main essential for rapid clam growth, as it 

 transports the food. The average south shore flats possess merely the 

 rise and fall of the tide, and as a rule have not the currents of the north 

 shore rivers. 



(4) The temperature of the northern waters is several degrees colder 

 than the waters south of Cape Cod. This affords, as has been shown 

 experimentally, a longer season of growth for the southern clam. The 

 north shore clam in the Essex region only increases the size of its shell 

 through the six summer months, while the south shore clam grows 

 slightly during the winter. 



The present advantages lie wholly with the north shore district, as 

 through overdigging the less extensive areas of southern Massachusetts 

 have become in most parts commercially barren. Overdigging has not 

 occurred to the same extent on the north shore, owing to the vast extent 

 of the flats. Nevertheless, many acres of these, as at Plymouth, 

 Kingston, Duxbury, and even Gloucester and Essex, have become wholly 

 or partially unproductive. The only important clamming in Massachu- 

 setts today is found in the towns bordering Ipswich Bay. The south 

 shore and a good part of the north shore furnish but few clams for 

 the market. 



