582 HISTOEY AND METHODS OF THE FISHEBIES. 



that is interesting. Take up one of those Mya clams, for instance, and look at it. The two 

 oblong, slight, bluish-white shells hold within an unintelligible yellowish mass, while projecting 

 from one end is a blackish, wrinkled lump that, upon being irritated, quickly withdraws, throwing 

 out at the same time a stream of water, while the shells shut tightly together. But put this 

 forbidding looking creature in a shallow pan of fresh sea-water 12 or 15 inches in length. Although 

 this, its natural element, is no doubt instantly grateful to it, the animal must be left quietly for a 

 few hours before it recovers confidence. Then the blackened tube of which a glimpse was 

 afforded before gradually protrudes from between the margins of the two halves or valves of the 

 shell, and slowly extends itself until a length of several inches is displayed. Now it is easy to see 

 that this organ has two openings at the end, beautifully fringed with appendages like little feelers, 

 and mottled with the richest brown. It really, then, consists of two tubes, one on top of the other, 

 leading to the body of the clam, and if you observe the openings closely, you will see a current of 

 water flowing into one of them, and another current pouring as steadily out of the other. These 

 currents are produced by the tremulous motion of innumerable minute hairs (cilia) that line the 

 interior of the animal. The extensile and contractile double tube is termed the "siphon," and the 

 currents "siphonal currents." 



The anatomy of the clam, like that of nearly all bivalved mollusks, is very simple. Forcing 

 them open, we find that the two halves of the shell are held together by a pair of strong muscles, 

 but if the animal would keep his doors quite closed he must exert a continued efi'ort, since immedi- 

 ately beneath the hinge, occupying a little cup-shaped projection like a bracket, is an elastic 

 substance which acts to throw the valves a little apart when the muscles are relaxed, just as a 

 piece of india-rubber squeezed into the hinge of a door would tend to open it as soon as the 

 pressure was removed. Having taken off one valve, we find lining it and the other as well a thin 

 membrane, called the mantle. The scalloped border which follows the edges of the shells is thick- 

 ened and united, except a small slit through which the " foot " projects at the eud opposite the 

 siphon. The foot is a tough and muscular organ serving as an excavator. Within the mantle are 

 the curtain-like gills, between which lie the muscles that operate the foot and siphon, the abdomen 

 and the viscera, which form the principal edible parts. The mouth is just under the forward 

 transverse muscle, and opens almost directly i;.to the stomach. The intestine, after several 

 turns, goes back directly through the heart to its orifice near the mouth. The ordinary length of 

 the shell is about 3 inches, but it is not uncommon to find it much larger, while the siphon may 

 be projected fully a foot. 



In this country the Mya clams are found from South Carolina to the Arctic Ocean, where the 

 seals, walrus, polar bear, and Arctic fox feed upon them whenever they have a chance. They are 

 scarce south of Cape Hatteras, and most abundant on the New England coast. They occur on the 

 northern coasts of Europe as far south as England and France, on the northeastern coast of Asia, 

 in Japan, and in Alaska. It is therefore essentially a northern species, and had the same general 

 distribution as far back as the pliocene and miocene ages of geology. 



Soft clams are everywhere denizens of the beach between tide-marks. The soil that suits 

 them best is sand, with a large admixture of gravel or mud, but all sorts of places are occupied 

 where the water is sufficiently brackish and where it is possible for them to burrow. The 

 specimens that live on the outer sandy beaches have a much whiter, thinner, and more regular 

 shell than those found in estuaries ; they are often really delicate in texture, and covered, even 

 when full grown, with a thin, yellowish epidermis, making a striking difference between them and 

 the homely, rough, mud-colored specimens usually seen in the markets. Now, as in 1616, wheu 

 dipt. John Smith wrote " You shal scarce find any Baye, Shallow Shore or Cove of sand, wyere 



