156 Our Food Mollusks 



difficult matter, and no entirely satisfactory method has 

 been devised for accomplishing it. Several devices have 

 been tried and abandoned. Two chief means of dealing 

 with them have been employed. In one case everything 

 lying on the bottom is removed by dredges. Ordinarily 

 this is too expensive, unless oysters thus dredged are in 

 need of culling. The second method is one recom- 

 mended by the United States Fish Commission, and is 

 universally employed; indeed, the oyster industry could 

 hardly exist in New England without it. 



Naturalists had for many years used a large mop made 

 of frayed rope ends for entangling and raising spiny 

 animals from the sea bottom. It was a modification of 

 this that the Fish Commission naturalists recommended 

 to the Connecticut oystermen. The starfish tangle, as 

 shown in the accompanying illustration (Figure 39), 

 consists of an iron or wooden bar from which depend 

 several chains or wires. On the latter, mops of frayed 

 rope or cotton waste are hung. The tangle is dragged 

 over the bottom, the spines of the starfish catch on the 

 mops, and the load is hoisted to the deck of the vessel 

 and plunged into a tank of hot water. 



The tangle does not sweep the bottom clean of star- 

 fish, but by its use their number is kept within bounds. 

 There is no danger that the pest may ever get beyond 

 control. There is great occasion for the southern planter 

 to be thankful that he knows nothing of such an oyster 

 foe. 



There are several species of snails that are destructive 

 to bivalves. Among these the large winkles or conchs 

 of northern shores do very little damage; but some of 

 the smaller forms, particularly the oyster drill, cause 

 large losses here and there along the Atlantic coast. 



