THE ECONOMIC MOLLUSCA OF ACADIA. 15 



given to poultry. From the Squids a kind of oil can be made, 

 though we believe it has little value commercially. 



Of the indirectly useful Molluscs, doubtless the most 

 important to man, are those which serve as food for the food- 

 fishes. A list of the Molluscs known to inhabit New England 

 waters, which are eaten by Cod, Haddock and other large fish, 

 is given in the '' History of Useful Aquatic Animals of the 

 United States, " pp. 693, 694 and 703. The majority of the 

 forms there mentioned occur in the waters of Acadia. It may 

 not be amiss to state here, that the stomachs of fishes are fine 

 hunting-ground for the conchologist, many species being 

 found in them, which are rare, or inaccessible in other ways. 



Indirectly also those Molluscs are beneficial to man, which, 

 by forming great tough beds, as the Edible Mussels do, protect 

 easily eroded sea-coasts from being washed away ; which bore 

 into and ultimately remove reefs and wrecks which are a bar 

 to safe navigation, as does the Teredo and its allies; and those 

 which are beneficial to the oyster industries, the most import- 

 ant of which is the Periwinkle {Littorina litorea), and some 

 others. 



Among the injurious Mollusca, the Ship-worms must take 

 first place. Species of Teredo are found all over the world, but 

 are most destructive in warm waters. They bore into and 

 destroy any kind of timber that is under the surface in pure 

 salt water. Hence, wharves, ships, buoys, breakwaters, are 

 all attacked, and naturalists and engineers have been put to 

 their wits' ends to study their habits and find a remedy. In 

 the following pages will be found some account of their 

 results. Ill Acadian waters we have some three or four species; 

 they are most troublesome upon the North Shore and Cape 

 Breton coast, where the warmer summer temperature affords 

 better conditions for the development of the young, than does 

 the much colder water of the Atlantic and Bay of Fundy 

 shores. Those Molluscs which bore into stone (Pholas and 

 allies) have never done any damage upon our shores. 



Among those which may be called indirectly injurious, are 

 those which are destructive to oyster-beds. In American 

 waters there are a number of these, the chief of which is the- 



