OYSTER-INDUSTRIES OF THE UNITED STATES. 287'' 



always found in the same latitudes, are so similar in taste that they 

 may be considered merely as varieties of the same species. Dr. Gould, 

 an American naturalist, admits this to be the case so far as the northern 

 and Canadian oysters are concerned. However the facts may be, the 

 difference between the American oyster and the European is so marked 

 that a superficial examination is sufficient to prove that they are of dis- 

 tinct species. The prominent points which distinguish those bivalves from 

 ours are the violet color of the muscular impression, and the greater 

 insipidity of taste, even when they are taken from banks situated on 

 the open coast, and in water entirely salt. 



{While the form of the common oyster of Europe, growing freely, is 

 almost entirely round, that of the American is always more or less elon. 

 gated. In addition to this, its lower valve is more concave, and contains 

 a mollusc thicker, more tender, richer in nutritive elements, and having 

 also a less salty taste, which in some cases resembles that of the mussel. 

 When it attains its full development, which, according to fishermen, 

 requires twenty years, its dimensions are considerably greater than 

 those of ours. Its shell is thicker and heavier, and the interior enamel 

 rarely presents those soft parts from which fetid water escapes when 

 they are accidentally pierced. 



The oyster of Virginia. — This, most common of the three species, has 

 a narrow shell, increasing gradually in size from the top and moderately 

 curved in the plane of the intersection of the valves when it is allowed 

 free development. The specimens taken from the natural banks" are 

 generally distorted, on account of certain conditions affecting their 

 growth ; but they nevertheless preserve all the most marked character- 

 istics of the species. 



As in Europe, the oyster which is most regularly an article of com- 

 merce is that which has been improved by culture. The beak of the 

 Virginia oyster, very pointed when old, is somewhat bent, and the oppo- 

 site part of the shell is rounded. The upper valve, almost entirely flat, 

 is the smoother of the two, and the surface, when not worn by friction, 

 presents numerous laminae more regularly disposed than in the other 

 species. The muscular impression, very often central, is of a deep violet 

 color. The weakness of the muscle is a marked characteristic of Amer- 

 ican oysters generally, a fact which I have not seen noticed in any book 

 upon natural history. 



Specimens are sometimes found measuring 15 English inches in length, 

 3£ in width. This species, known in the market under the name of the 

 Chesapeake oyster, is common all along the coast, especially in the 

 Southern States. In the North it is found in as high latitudes as Prince 

 Edward Island and the mouth of the Saint Lawrence River. Its most 

 essential characteristics are its great length, compared with its width, 

 and the pyramidal form of the beak. 



The Northern oyster has a shell rounded, curved, ordinarily crooked, 

 and always less elongated than that of the preceding species. The upper 



